- A novel and environmentally friendly colorimetric method for detection of cystine in human urine using unmodified gold nanoparticles
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Cystine was reduced by ascorbic acid to cysteine, which induced the aggregation of unmodified gold nanoparticles. The accompanied color change was distinguishable and perceivable by the naked eye. This facile assay method was successfully applied to the detection of cystine in human urine.
- Lu, Li-Qiang,Gao, Qian,Song, Chi,Tian, Xi-Ke,Xu, An-Wu
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- Characterization of an aspergillus oryzae cysteinyl dipeptidase expressed in escherichia coli
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Cysteinyl dipeptidase from Aspergillus oryzae (CdpA) was produced in Escherichia coli and purified. The enzyme showed activity specific toward cysteinecontaining dipeptides, but its substrate specificity was distinct from those of other cysteinyl dipeptidases of the M20 family. It was optimally active at pH 7-8 and stable at pH 6-9 and at up to 40°C.
- Hattori, Ryota,Matsushita-Morita, Mayumi,Marui, Junichiro,Tada, Sawaki,Suzuki, Satoshi,Furukawa, Ikuyo,Yamagata, Youhei,Amano, Hitoshi,Ishida, Hiroki,Takeuchi, Michio,Kusumoto, Ken-Ichi
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- Biogenesis of Hydrogen Sulfide and Thioethers by Cystathionine Beta-Synthase
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Aims: The transsulfuration pathway enzymes cystathionine beta-synthase (CBS) and cystathionine gamma-lyase are thought to be the major source of hydrogen sulfide (H2S). In this study, we assessed the role of CBS in H2S biogenesis. Results: We show that despite discouraging enzyme kinetics of alternative H2S-producing reactions utilizing cysteine compared with the canonical condensation of serine and homocysteine, our simulations of substrate competitions at biologically relevant conditions suggest that cysteine is able to partially compete with serine on CBS, thus leading to generation of appreciable amounts of H2S. The leading H2S-producing reaction is condensation of cysteine with homocysteine, while cysteine desulfuration plays a dominant role when cysteine is more abundant than serine and homocysteine is limited. We found that the serine-to-cysteine ratio is the main determinant of CBS H2S productivity. Abundance of cysteine over serine, for example, in plasma, allowed for up to 43% of CBS activity being responsible for H2S production, while excess of serine typical for intracellular levels effectively limited such activity to less than 1.5%. CBS also produced lanthionine from serine and cysteine and a third of lanthionine coming from condensation of two cysteines contributed to the H2S pool. Innovation: Our study characterizes the H2S-producing potential of CBS under biologically relevant conditions and highlights the serine-to-cysteine ratio as the main determinant of H2S production by CBS in vivo. Conclusion: Our data clarify the function of CBS in H2S biogenesis and the role of thioethers as surrogate H2S markers.
- Majtan, Tomas,Krijt, Jakub,Sokolová, Jitka,K?í?ková, Michaela,Ralat, Maria A.,Kent, Jana,Gregory, Jesse F.,Ko?ich, Viktor,Kraus, Jan P.
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- Developing potent backbone cyclic peptides bearing the shared epitope sequence as rheumatoid arthritis drug-leads
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Rheumatoid arthritis (RA) is a common human leukocyte antigen-associated disease. Most RA patients have a five-residue sequence motif called the shared epitope (SE) in the DRβ-chain of the HLA-DRB1 protein. The SE was found to activate nitric oxide (NO) production, suggesting a possible mechanism for RA development. The native conformation of the SE is presumed to be an α-helix, thus using cyclic peptides to stabilize this conformation may produce a potent SE mimetic which will have drug-like properties. We present the development of a backbone cyclic SE mimetic that activates NO production in the low nM range. Circular dichroism analysis revealed a conformational change from for the parent linear peptides to the cyclic analogs. The most active cyclic analog is completely stable towards trypsin/chymotrypsin degradation while the linear 15-mer analogs completely degraded within 30 min. The outcome of this study is a potent cyclic peptide with drug-like properties that can be used as a template for drug development.
- Naveh, Shirly,Tal-Gan, Yftah,Ling, Song,Hoffman, Amnon,Holoshitz, Joseph,Gilon, Chaim
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- Redox metabolism in Trypanosoma cruzi. Biochemical characterization of dithiol glutaredoxin dependent cellular pathways
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In Trypanosoma cruzi, the modification of thiols by glutathionylation-deglutathionylation and its potential relation to protective, regulatory or signaling functions have been scarcely explored. Herein we characterize a dithiolic glutaredoxin (TcrGrx), a redox protein with deglutathionylating activity, having potential functionality to control intracellular homeostasis of protein and non-protein thiols. The catalytic mechanism followed by TcrGrx was found dependent on thiol concentration. Results suggest that TcrGrx operates as a dithiolic or a monothiolic Grx, depending on GSH concentration. TcrGrx functionality to mediate reduction of protein and non-protein disulfides was studied. TcrGrx showed a preference for glutathionylated substrates respect to protein disulfides. From in vivo assays involving TcrGrx overexpressing parasites, we observed the contribution of the protein to increase the general resistance against oxidative damage and intracellular replication of the amastigote stage. Also, studies performed with epimastigotes overexpressing TcrGrx strongly suggest the involvement of the protein in a cellular pathway connecting an apoptotic stimulus and apoptotic-like cell death. Novel information is presented about the participation of this glutaredoxin not only in redox metabolism but also in redox signaling pathways in T. cruzi. The influence of TcrGrx in several parasite physiological processes suggests novel insights about the protein involvement in redox signaling.
- Márquez, Vanina E.,Arias, Diego G.,Chiribao, Maria L.,Faral-Tello, Paula,Robello, Carlos,Iglesias, Alberto A.,Guerrero, Sergio A.
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- Racemization of Optically Active Cysteine via Formation of 2,2-Dimethyl-4-thiazolidinecarboxylic Acid
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Optically active cysteine (Cys) was racemized via formation of (RS)-2,2-dimethyl-4-thiazolidinecarboxylic acid ((RS)-DMT) by refluxing in the presence of acetone in 10-fold molar amount in acetic acid.The formed (RS)-DMT was hydrolyzed by adding water to the reaction mixture to give (RS)-Cys in 95-97percent yield.
- Shiraiwa, Tadashi,Kataoka, Kazuo,Sakata, Shinji,Kurokawa, Hidemoto
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- Facile dimethylarsenic exchange and pyramidal inversion in its cysteine and glutathione adducts
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Rapid thiolate exchange of dimethylarsonium, Me2As+, is observed between two different thiolate species in solution. NMR is used to characterize the equilibrium constants for interthiol transfer as well the rapid intra molecular conf
- Bohle, D. Scott,Gu, Yuxuan
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- Racemic Structure and Optical Resolution by Preferential Crystallization of DL-Cysteine Salts of Substituted Benzenesulfonic Acids
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Infrared absorption spectrum, solubility, and thermodynamic analysis indicated that DL-cysteine salts of benzenesulfonic acid (DL-BA salt) and 4-ethylbenzenesulfonic acid (DL-4-EB salt) are conglomerates at room temperature, but DL-BA salt forms a racemic compound at the melting point.These DL-salts were optically resolved by the preferential crystallization.As for DL-4-EB salt, suitable conditions were estimated by the free energy of critical nucleation in supersaturated solutions.The successive preferential crystallization in ethanol at 20 deg C was found to give D- and L-4-EB salts with optical purity of 97-100percent in the resolution yield of 83-90percent.Purification and following treatment with triethylamine gave optically pure D- and L-Cys's.
- Shiraiwa, Tadashi,Tazoh, Hirohide,Sunami, Michio,Sado, Yujin,Kurokawa, Hidemoto
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- Thermostability and reactivity in organic solvent of O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1
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O-phospho-L-serine sulfhydrylase (OPSS) from archaeon Aeropyrum pernix K1 is able to synthesize L-cysteine even at 80 °C. In this article, we compared thermal stability and reactivity in organic solvent of OPSS with those of O-acetyl-L-serine sulfhydrylase B (OASS-B) from Escherichia coli. As a result, the thermostability of OPSS was much higher than that of OASS-B. Moreover, the activity of OPSS increased in the reaction mixture containing the organic solvent, such as N, N'-dimethyl formamide and 1,4-dioxane, whereas that of OASS-B gradually decreased as the content of organic solvent increased. From the crystal structural analysis, the intramolecular electrostatic interactions of N-terminal domain in OPSS seemed to be correlated with the tolerance of OPSS to high temperature and organic solvent. These results indicate that OPSS is more superior to OASS-B for the industrial production of L-cysteine and unnatural amino acids that are useful pharmaceuticals in the presence of organic solvent.
- Nakamura, Takashi,Asai, Shinji,Nakata, Kaori,Kunimoto, Kohei,Oguri, Masateru,Ishikawa, Kazuhiko
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- Electrochemical Studies of Poly(mercaptohydroquinone) and Poly(mercapto-p-benzoquinone) Films Prepared by Electrochemical Polymerization. VI. Electroreduction of L-Cystine on Thiolates Fixed in the Polymer Film
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Electrocatalytic reduction of L-cystine (CySSCy) was examined on glassy carbon electrodes coated with the title conductive polymer in which Pt, Pd, Cu, Ag, and Hg thiolates were fixed.Pt and/or Pd thiolate fixed in the polymer behaved as excellent electrocatalytic active sites for reductive cleavage of the sulfur-sulfur bond in CySSCy.
- Arai, Gorou,Sugaya, Toshiaki,Sakamoto, Mika,Yasumori, Iwao
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- The structural and mutational analyses of O-ureido-L-serine synthase necessary for D-cycloserine biosynthesis
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We have recently been successful in cloning a gene cluster necessary for the biosynthesis of d-cycloserine (d-CS) from d-CS-producing Streptomyces lavendulae ATCC11924. Although dcsD, one of the ORFs located on the gene cluster, encodes a protein homologous to O-acetylserine sulfhydrylase that synthesizes l-cysteine using O-acetyl-l-serine together with sulfide, it functions to form O-ureido-l-serine as a d-CS biosynthetic intermediate, using O-acetyl-l-serine together with hydroxyurea (HU). In the present study, using crystallographic and mutational studies, three amino acid residues in DcsD that are important for the substrate preference toward HU were determined. We showed that two of the three residues are important for the binding of HU into the substrate-binding pocket. The other residue contributes to the formation of a loose hydrogen-bond network during the catalytic reaction. Information regarding the amino acid residues will be very useful in the design of a new catalyst for synthesizing the β-substituted-L-alanine derivatives.
- Uda, Narutoshi,Matoba, Yasuyuki,Oda, Kosuke,Kumagai, Takanori,Sugiyama, Masanori
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- Seleno-auranofin (Et3PAuSe-tagl): Synthesis, spectroscopic (EXAFS, 197Au Moessbauer, 31P, 1H, 13C, and 77Se NMR, ESI-MS) characterization, biological activity, and rapid serum albumin-induced triethylphosphine oxide generation
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Seleno-auranofin (SeAF), an analogue of auranofin (AF), the orally active antiarthritic gold drug in clinical use, was synthesized and has been characterized by an array of physical techniques and biological assays. The Moessbauer and extended X-ray absorption fine structure (EXAFS) parameters of the solid compound demonstrate a linear P-Au-Se coordination environment at a gold(I) center, analogous to the structure of auranofin. The 31P, 13C, and 1H NMR spectra of SeAF in chloroform solution closely resemble those of auranofin. The 77Se spectrum consists of a singlet at 481 ppm, consistent with a metal-bound selenolate ligand. The absence of 2JPSe coupling in the 31P and 77Se spectra may arise from dynamic processes occurring in solution or because the 2JPSe coupling constants are smaller than the observed bandwidths. Electrospray ionization mass spectrometry (ESI-MS) spectra of SeAF in 50:50 methanol-water exhibited strong signals for [(Et 3P)2Au]+, [(Et3PAu) 2-μ-Se-tagl]+, and [Au(Se-tagl)2] -, which arise from ligand scrambling reactions. Three assays of the anti-inflammatory activity of SeAF allowed comparison to AF. SeAF exhibited comparable activity in the topically administered murine arachadonic acid-induced and phorbol ester-induced anti-inflammatory assays but was inactive in the orally administered carragenan-induced assay in rats. However, in vivo serum gold levels were comparable in the rat, suggesting that differences between the in vivo metabolism of the two compounds, leading to differences in transport to the inflamed site, may account for the differential activity in the carrageenan-induced assay. Reactions of serum albumin, the principal transport protein of gold in the serum, demonstrated formation of AlbSAuPEt3 at cysteine 34 and provided evidence for facile reduction of disulfide bonds at cysteine 34 and very rapid formation of Et3P=O, a known metabolite of auranofin.
- Hill, David T.,Isab, Anvarhusein A.,Griswold, Don E.,Dimartino, Michael J.,Matz, Elizabeth D.,Figueroa, Angel L.,Wawro, Joyce E.,Debrosse, Charles,Reiff, William M.,Elder, Richard C.,Jones, Benjamin,Webb, James W.,Shaw, C. Frank
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- Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
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Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
- De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
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supporting information
p. 4904 - 4909
(2021/06/16)
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- Synthesis method of DL-cysteine
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The invention discloses a synthetic method of DLcysteine. The method comprises the following steps: by using acrylonitrile as a raw material, chlorinating to generate 2, 3dichloropropionitrile, hydrolyzing to generate corresponding acid, reacting the acid with thiourea to cyclize to generate 2-aminothiazoline-4-carboxylic acid, adding alkali sulfide to generate 2-mercaptothiazoline-4-carboxylic acid, and hydrolyzing to generate cysteine. The synthesis method provided by the invention has the advantages of short synthesis steps, mild preparation conditions, sufficient and cheap raw material sources and higher product yield.
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Paragraph 0020-0022
(2021/02/13)
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- MODIFIED INTERLEUKIN-7 PROTEINS AND USES THEREOF
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Provided are a modified IL-7 polypeptide and a fusion protein containing the modified IL-7 polypeptide. The fusion protein of the modified IL-7 includes: a first domain containing an interleukin-7 polypeptide; a second domain containing an oligopeptide having 1 to 10 amino acid residues (with proviso that the second domain excludes the oligopeptide consisting of methionine and/or glycine); and (c) a third domain which prolongs the half-life of the IL-7 fusion protein. The modified IL-7 polypeptide is composed of the (a) first domain and the (b) second domain. The modified IL-7 polypeptide and the fusion protein are expressed in a higher yield than the wild-type IL-7 and shows increased stability.
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- Cysteine Chemistry in Connection with Abiogenesis
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Theoretical and experimental work has been conducted about possible prebiotic syntheses of cysteine. Activated derivatives of this amino acid can oligomerize and polymerize to afford various poly-thiazolines and cysteine-rich chains.
- Bridoux, Maxime,Ceccarelli, Cecilia,Shalayel, Ibrahim,Vallée, Yannick,Vazart, Fanny,Youssef-Saliba, Sparta
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supporting information
(2020/05/18)
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- Dynamic Kinetic Resolution for Asymmetric Synthesis of L-Noncanonical Amino Acids from D-Ser Using Tryptophan Synthase and Alanine Racemase
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L-Ser is often used to synthesize some significant l-noncanonical α-amino acids(l-ncAAs), which are the prevalent intermediates and precursors for functional synthetic compounds. In this study, threonine aldolase from Escherichia coli k-12 MG1655 has been used to synthesize l-Ser. In contrast to the maximum catalytic capacity (20 g/L) for l-threonine aldolase(LTA), d-Ser was synthesized with high yield (240 g/L) from cheap Gly and paraformaldehyde using d-threonine aldolase (DTA) from Arthrobacter sp ATCC. In order to fully utilize d-Ser and expand the resource of l-Ser, a dynamic kinetic resolution system was constructed to convert d/dl-Ser to l-Ser through combining alanine racemase (Alr) from Bacillus subtilis with l-tryptophan synthase (TrpS) from Escherichia coli k-12 MG1655, and l-ncAAs including l-Trp and l-Cys derivatives were synthesized with excellent enantioselectivity and in high yields. The results indicated l-ncAAs could be efficiently synthesized from d-Ser using this original and green dynamic kinetic resolution system, and the reliable l-Ser resource has been established from simple and achiral substrates.
- Yu, Jinhai,Li, Jing,Gao, Xia,Zeng, Shuiyun,Zhang, Hongjuan,Liu, Junzhong,Jiao, Qingcai
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p. 6618 - 6625
(2019/11/03)
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- Preparation and characterization of a new open-tubular capillary column for enantioseparation by capillary electrochromatography
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In order to use the enantioseparation capability of cationic cyclodextrin and to combine the advantages of capillary electrochromatography (CEC) with open-tubular (OT) column, in this study, a new OT-CEC, coated with cationic cyclodextrin (1-allylimidazolium-β-cyclodextrin [AI-β-CD]) as chiral stationary phase (CSP), was prepared and applied for enantioseparation. Synthesized AI-β-CD was characterized by infrared (IR) spectrometry and mass spectrometry (MS). The preparation conditions for the AI-β-CD-coated column were optimized with the orthogonal experiment design L9(34). The column prepared was characterized by scanning electron microscopy (SEM) and elemental analysis (EA). The results showed that the thickness of stationary phase in the inner surface of the AI-β-CD-coated columns was about 0.2 to 0.5?μm. The AI-β-CD content in stationary phase based on the EA was approximately 2.77?mmol·m?2. The AI-β-CD-coated columns could separate all 14 chiral compounds (histidine, lysine, arginine, glutamate, aspartic acid, cysteine, serine, valine, isoleucine, phenylalanine, salbutamol, atenolol, ibuprofen, and napropamide) successfully in the study and exhibit excellent reproducibility and stability. We propose that the column, coated with AI-β-CD, has a great potential for enantioseparation in OT-CEC.
- Li, Yingjie,Tang, Yimin,Qin, Shili,Li, Xue,Dai, Qiang,Gao, Lidi
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p. 283 - 292
(2019/02/05)
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- Dehalogenation of Halogenated Nucleobases and Nucleosides by Organoselenium Compounds
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Halogenated nucleosides, such as 5-iodo-2′-deoxyuridine and 5-iodo-2′-deoxycytidine, are incorporated into the DNA of replicating cells to facilitate DNA single-strand breaks and intra- or interstrand crosslinks upon UV irradiation. In this work, it is shown that the naphthyl-based organoselenium compounds can mediate the dehalogenation of halogenated pyrimidine-based nucleosides, such as 5-X-2′-deoxyuridine and 5-X-2′-deoxycytidine (X=Br or I). The rate of deiodination was found to be significantly higher than that of the debromination for both nucleosides. Furthermore, the deiodination of iodo-cytidines was found to be faster than that of iodo-uridines. The initial rates of the deiodinations of 5-iodocytosine and 5-iodouracil indicated that the nature of the sugar moiety influences the kinetics of the deiodination. For both the nucleobases and nucleosides, the deiodination and debromination reactions follow a halogen-bond-mediated and addition/elimination pathway, respectively.
- Mondal, Santanu,Mugesh, Govindasamy
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p. 1773 - 1780
(2019/01/10)
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- Facile Synthesis of S-Substituted L-Cysteines with Nano-sized Immobilized O-Acetylserine Sulfhydrylase
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Many S-substituted l-cysteines are useful pharmaceutical intermediates but require a simple synthesis method. Here we developed enzymatic synthesis of several S-aryl-l-cysteines and S-benzyl-l-cysteine directly from O-acetylserine (OAS) with immobilized O-acetylserine sulfhydrylase CysM. Novel iron-oxide magnetic nanoparticles (MNPs) with cobalt-nitrilotriacetic acid function were prepared with a diameter of 80 nm in 75 % yield. Direct immobilization of His-tagged CysM in the cell-free extract on the MNPs via affinity attachment afforded stable nanobiocatalyst with 97 % enzyme loading efficiency and 93 % free enzyme activity. The immobilized enzyme catalyzed the biotransformation of benzylthiol and OAS to give S-benzyl-l-cysteine in 88 % yield. The nanobiocatalyst also demonstrated high recyclability, retaining 95 % productivity in the fifth cycle. The immobilized CysM accepts various arylthiols to react with OAS, giving rise to a new synthesis route of several S-substituted l-cysteines in 60–96 % yield.
- Vahidi, Akbar K.,Wang, Zunsheng,Li, Zhi
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p. 3671 - 3674
(2018/09/12)
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- T Cells with Increased Immunosuppression Resistance
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This invention relates to the treatment of cancer in an individual by administration of a population of modified T cells that express a recombinant cAMP phosphodiesterase (PDE) or a fragment thereof and an antigen receptor which binds specifically to cancer cells in the individual. Populations of modified T cells and methods of producing populations of modified T cells are provided, along with pharmaceutical compositions and methods of treatment
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- Purification, structural characterization and bioactivity evaluation of a novel proteoglycan produced by Corbicula fluminea
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A novel proteoglycan, named CFPS-11, was isolated from Corbicula fluminea, which is a food source of freshwater bivalve mollusk. CFPS-11 had an average molecular weight of 807.7 kDa and consisted of D-glucose and D-glucosamine in a molar ratio of 12.2:1.0. The protein moiety (~5%) of CFPS-11 was covalently bonded to the polysaccharide chain in O-linkage type through both serine and thereonine residues. The polysaccharide chain of CFPS-11 was composed of (1 → 4)-α-D-glucopyranosyl and (1 → 3,6)-α-D-glucopyranosyl residues, which branched at O-6. The branch chain consisted of (1 →)-α-D-glucopyranosyl and (1 →)-α-D-N-acetylglucosamine residues. CFPS-11 exhibited significant antioxidant activity in a dose-dependent manner and remarkable inhibition activities against α-amylase and α-glucosidase by in vitro assays. These findings indicated that the CFPS-11 from C. fluminea has the potential for development as a health food ingredient.
- Yan, Jing-Kun,Wang, Yao-Yao,Qiu, Wen-Yi,Wu, Li-Xia,Ding, Zhi-Chao,Cai, Wu-Dan
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- Chromatographic Resolution of α-Amino Acids by (R)-(3,3'-Halogen Substituted-1,1'-binaphthyl)-20-crown-6 Stationary Phase in HPLC
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Three new chiral stationary phases (CSPs) for high-performance liquid chromatography were prepared from R-(3,3'-halogen substituted-1,1'-binaphthyl)-20-crown-6 (halogen = Cl, Br and I). The experimental results showed that R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 (CSP-1) possesses more prominent enantioselectivity than the two other halogen-substituted crown ether derivatives. All twenty-one α-amino acids have different degrees of separation on R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6-based CSP-1 at room temperature. The enantioselectivity of CSP-1 is also better than those of some commercial R-(1,1'-binaphthyl)-20-crown-6 derivatives. Both the separation factors (α) and the resolution (Rs) are better than those of commercial crown ether-based CSPs [CROWNPAK CR(+) from Daicel] under the same conditions for asparagine, threonine, proline, arginine, serine, histidine and valine, which cannot be separated by commercial CR(+). This study proves the commercial usefulness of the R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 chiral stationary phase.
- Wu, Peng,Wu, Yuping,Zhang, Junhui,Lu, Zhenyu,Zhang, Mei,Chen, Xuexian,Yuan, Liming
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supporting information
p. 1037 - 1042
(2017/07/25)
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- Protection of Endogenous Thiols against Methylmercury with Benzimidazole-Based Thione by Unusual Ligand-Exchange Reactions
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Organomercurials, such as methylmercury (MeHg+), are among the most toxic materials to humans. Apart from inhibiting proteins, MeHg+ exerts its cytotoxicity through strong binding with endogenous thiols cysteine (CysH) and glutathione (GSH) to form MeHgCys and MeHgSG complexes. Herein, it is reported that the N,N-disubstituted benzimidazole-based thione 1 containing a N?CH2CH2OH substituent converts MeHgCys and MeHgSG complexes to less toxic water-soluble HgS nanoparticles (NPs) and releases the corresponding free thiols CysH and GSH from MeHgCys and MeHgSG, respectively, in solution by unusual ligand-exchange reactions in phosphate buffer at 37 °C. However, the corresponding N-substituted benzimidazole-based thione 7 and N,N-disubstituted imidazole-based thione 3, in spite of containing a N?CH2CH2OH substituent, failed to convert MeHgX (X=Cys, and SG) to HgS NPs under identical reaction conditions, which suggests that not only the N?CH2CH2OH moiety but the benzimidazole ring and N,N-disubstitution in 1, which leads to the generation of a partial positive charge at the C2 atom of the benzimidazole ring in 1:1 MeHg-conjugated complex of 1, are crucial to convert MeHgX to HgS NPs under physiologically relevant conditions.
- Banerjee, Mainak,Karri, Ramesh,Chalana, Ashish,Das, Ranajit,Rai, Rakesh Kumar,Rawat, Kuber Singh,Pathak, Biswarup,Roy, Gouriprasanna
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supporting information
p. 5696 - 5707
(2017/04/28)
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- Unnatural amino acid synthesis by thermostable O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1
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O-Acetyl-L-serine sulfhydrylase (OASS) from plants and bacteria synthesizes cysteine and unnatural amino acids that are important building blocks for active pharmaceuticals and agrochemicals. A thermostable O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1 (OPSSAp) exhibits a function similar to OASS. In the present study, we examined the synthesis of various unnatural amino acids using OPSSAp and demonstrated OPSSAp could efficiently synthesize various sulfur-containing amino acids. OPSSAp would be useful for industrial production of biologically important unnatural amino acids.
- Nakamura, Takashi,Kunimoto, Kohei,Yuki, Toru,Ishikawa, Kazuhiko
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supporting information
p. 1789 - 1792
(2017/11/23)
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- (-)/(+)-Sparteine induced chirally-active carbon nanoparticles for enantioselective separation of racemic mixtures
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Chiral carbon nanoparticles (CCNPs) were developed by surface passivation using the chiral ligand (-)-sparteine or (+)-sparteine (denoted (-)-SP/CNP and (+)-SP/CNP, respectively). The chirality of the prepared CCNPs was demonstrated by circular dichroism
- Vulugundam, Gururaja,Misra, Santosh K.,Ostadhossein, Fatemeh,Schwartz-Duval, Aaron S.,Daza, Enrique A.,Pan, Dipanjan
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p. 7513 - 7516
(2016/06/14)
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- Crystal structure, computational studies, and stereoselectivity in the synthesis of 2-aryl-thiazolidine-4-carboxylic acids via in situ imine intermediate
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ABSTRACT: This article presents the synthesis of (2R/2S,4R)-2-aryl-thiazolidine-4-carboxylic acids via nucleophilic addition of L-Cysteine on aromatic aldehydes involving a yield and time-effective room temperature reaction in an aqueous DMSO medium in the presence of NaHCO3 as a base. The synthesized diastereomers were spectroscopically characterized and quantified for diastereomeric excess by liquid chromatography-mass spectrometry analysis. The impact of the type and position of substituent in aromatic aldehydes on reaction time, % yield, 1H NMR shift at newly formed chiral center [C(2)-H], and diastereomeric excess (de%) have been investigated. A plausible mechanism for stereoselectivity via an in situ imine intermediate is proposed using real-time IR monitoring of the synthetic reaction based on the significant signals at 1597, 1593 cm?1 for imine (C=N) stretching. The imine mechanism for stereoselectivity was further supported by NMR studies of azomethine 13C NMR signals at 159, 160 δ ppm and by the single crystal structure of hitherto unknown (2S,4R)-3-(tert-butoxycarbonyl)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid (3a) obtained as a major diastereomer in the synthesis of the butyloxy carbonyl (BOC) derivative of (2R/2S,4R)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid. The significant ortho-OH effect of phenolic hydroxyl group leading to strong hydrogen bondings plays a vital role in the formation of 2S,4R BOC derivative stereoselectively. The frontier molecular orbitals, possible electronic excitations, IR band characterizations, and reactivity parameters of newly reported compound (3a) have been predicted using quantum chemical descriptors from density functional theory. The theoretical exploration of experimental spectra using time-dependent DFT indicated a (π–π*) transition between HOMO and LUMO in the ultraviolet region. (Figure presented.)
- Jagtap, Rohidas M.,Rizvi, Masood A.,Dangat, Yuvraj B.,Pardeshi, Satish K.
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p. 401 - 425
(2016/07/23)
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- A novel thyroglobulin-binding lectin from the brown alga Hizikia fusiformis and its antioxidant activities
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A lectin (HFL) was isolated from the brown alga, Hizikia fusiformis, through ion exchange on cellulose DE52 and HPLC with a TSK-gel G4000PWXL column. SDS-PAGE showed that HFL had a molecular mass of 16.1 kDa. The HPLC (with a TSK-gel G4000PWXL column) indicated that HFL is a tetramer in its native state. The total carbohydrate content was 41%. Glucose, galactose and fucose were the monosaccharide units of HFL, and the normalized mol% values were 6, 14 and 80, respectively. HFL contains a large amount of the acidic amino acid, Asx. The β-elimination reaction suggested that the oligosaccharide and peptide moieties of HFL may belong to the N-glucosidic linkage. The amino acid sequences, of about five segments of HFL, were acquired by MALDI-TOF/TOF, and the sequences have no homology with other lectins. HFL was found to agglutinate sheep erythrocytes. The hemagglutination activity was inhibited by thyroglobulin, from bovine thyroid, but not by any of the monosaccharides tested. The lectin reaction was independent of the presence of the divalent cation Ca2+. HFL showed free radical scavenging activity against hydroxyl, DPPH and ABTS+ radicals.
- Wu, Mingjiang,Tong, Changqing,Wu, Yue,Liu, Shuai,Li, Wei
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- Reaction of hydrogen sulfide with disulfide and Sulfenic acid to form the strongly Nucleophilic Persulfide
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Background: Hydrogen sulfide (H2S) modulates physiological processes in mammals. Results: The reactivity of H2S toward disulfides (RSSR) and albumin sulfenic acid (RSOH) to form persulfides (RSSH) was assessed. Conclusion: H2S is less reactive than thiols. Persulfides have enhanced nucleophilicity. Significance: This kinetic study helps rationalize the contribution of the reactions with oxidized thiol derivatives toH2S biology.
- Cuevasanta, Ernesto,Lange, Mike,Bonanata, Jenner,Coiti?o, E. Laura,Ferrer-Sueta, Gerardo,Filipovic, Milos R.,Alvarez, Beatriz
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p. 26866 - 26880
(2015/11/17)
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- POLYPEPTIDES, NUCLEIC ACIDS AND USES THEREOF
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We describe an ELABELA polypeptide comprising a sequence CXXXRCXXXHSRVPFP (SEQ ID NO: 1), in which X signifies an amino acid residue, such as a sequence selected from the group consisting of: SEQ ID NO: 2 to SEQ ID NO: 18, preferably CLQRRCMPLHSRVPFP (SEQ ID NO: 2), or a fragment, homologue, variant or derivative thereof, which polypeptide is capable of maintaining self-renewal and/or pluripotency of a stem cell.
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Page/Page column
(2015/06/10)
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- Anti-fibroblast activation protein antibodies and methods and uses thereof
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Specific binding members, particularly antibodies and fragments thereof, which bind to Fibroblast Activation Protein (FAP) are provided, particularly recognizing both human and mouse FAP. These antibodies are useful in the diagnosis and treatment of conditions associated with activated stroma, including wound healing, epithelial cancers, osteoarthritis, rheumatoid arthritis, cirrhosis and pulmonary fibrosis. The anti-FAP antibodies, variable regions or CDR domain sequences thereof, and fragments thereof may also be used in therapy in combination with chemotherapeutics, immune modulators, or anti-cancer agents and/or with other antibodies or fragments thereof. Antibodies of this type are exemplified by the novel antibodies ESC1 1 and ESC 14 whose sequences are provided herein.
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- METHODS FOR TREATING MUSCLE SPECIFIC RECEPTOR KINASE MYASTHENIA GRAVIS
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Agents, compositions, and medicaments that reduce interactions between muscle specific kinase receptor (MuSK) and pathogenic immunoglobulin G4 (IgG4) antibodies specific for the first Ig-like domain of MuSK and methods and uses thereof to reduce such interactions are encompassed herein. Also encompassed are screening assays to identify inhibitors of these pathogenic antibodies, particularly those that reduce binding to MuSK. Agents identified using the screening assays described herein are envisioned for use as therapeutics, alone or in compositions or in medicaments, to improve motor function in subjects afflicted MuSK-MG.
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- FUNCTIONALIZED FLUORINE CONTAINING PHTHALOCYANINE MOLECULES
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Functionalized fluorine containing phthalocyanine molecules, methods of making, and methods of use in diagnostic applications and disease treatment are disclosed herein. In some embodiments, the fluorine containing phthalocyanine molecules are functionalized with a reactive functional group or at least one cancer-targeting ligand (CTL). The CTL can facilitate more efficient binding and/or internalization to a cancer cell than to a healthy cell. The CTL can inhibit expression of oncoprotein in some embodiments. The pthalocyanine moiety can be used in diagnostic applications, such as fluorescence labeling of a cancer cell, and/or treatment applications, such as catalyzing formation of a reactive oxygen species (ROS) which can contribute to cell death of a cancer cell.
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- Antibody molecules having specificity for human OX40
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The invention relates to antibody molecules having specificity for antigenic determinants of human OX40, therapeutic uses of the antibody molecules and methods for producing said antibody molecules.
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- Light activation of protein splicing with a photocaged fast intein
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Intein-mediated protein splicing has found broad biotechnological applications. Herein, we describe our recent result in engineering a photoactivatable intein compatible with living mammalian cells. A photocaged cysteine amino acid residue was genetically introduced into a highly efficient Nostoc punctiforme (Npu) DnaE intein. The resulting photocaged intein was inserted into a red fluorescent protein (RFP) mCherry and a human Src tyrosine kinase to create inactive chimeric proteins. A light-induced photochemical reaction was able to reactivate the intein and trigger protein splicing. Active mCherry and Src were formed as observed by direct fluorescence imaging or imaging of an Src kinase sensor in mammalian cells. The genetically encoded photocaged intein is a general optogenetic tool, allowing effective photocontrol of primary structures and functions of proteins.
- Ren, Wei,Ji, Ao,Ai, Hui-Wang
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supporting information
p. 2155 - 2158
(2015/03/04)
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- Degradation and antioxidant activities of peptides and zinc-peptide complexes during in vitro gastrointestinal digestion
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The degradation characteristics of three peptides (Ser-Met, Asn-Cys-Ser, and glutathione) and their zinc-peptide complexes were studied using a two-stage in vitro digestion model. Enzyme-resistant peptides and zinc-peptide complexes, antioxidant activities, and free amino acids released by digestive enzymes, were measured in this study. The results revealed that the three peptides and their zinc-peptide complexes were resistant to pepsin but not to pancreatin. Pancreatin can partly hydrolyse both peptides and zinc-peptide complexes, but more than half of them remaining in their original form after gastrointestinal digestion. The coordination of zinc improved the enzymatic resistance of the peptide due to lower solubility of complexes and affected the hydrolytic site of pepsin and pancreatin. Zinc-Asn-Cys-Ser, which is highly resistant to enzymatic hydrolysis and maintains Zn in a soluble form, may have potential to improve Zn bioavailability.
- Wang, Chan,Li, Bo,Wang, Bo,Xie, Ningning
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p. 733 - 740
(2015/01/09)
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- Iodate oxidation of n-acetyl l-cysteine: Application in drug determination and characterization of its oxidation and degradation product by mass spectrometry
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A kinetic spectrophotometric method based on the initial rate measurement has been developed for the determination of N-acetyl L-cysteine. The developed method is based on the oxidation of N-acetyl L-cysteine with iodate. The reaction product was studied and characterized using the mass spectrometry and the structure of the product was proposed. From the mass spectrometric studies it was concluded that the oxidation of the drug resulted in the formation of a disulfide. The developed method was validated as per the guidelines of international conference on harmonization. The developed initial rate method was found to be linear in the concentration range of 1.25-30 μg ml-1. The detection and quantitation limits were found to be 0.018 and 0.056 μg ml-1. In the current study, the degradation product of N-acetyl L cysteine was also prepared and identified using mass spectrometry.
- Siddiqui, Masoom Raza,Wabaidur, Saikh Mohammad,Alothman, Zied A.,Rahman, Habibur,Alam, Md.Sarfaraz,Ali, Md.Sajid
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p. 2303 - 2307
(2014/07/22)
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- REGULATORY NETWORK FOR Th17 SPECIFICATION AND USES THEREOF
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Screening assays and methods of using same for screening to identify modulator agents or compounds that affect Th17 cell specification are described herein. Pharmaceutical compositions comprising agents or compounds that modulate Th17 cell specification are also encompassed. Methods for modulating Th17 cell specification using agents identified using assays described herein in pharmaceutical compositions are also envisioned. Such pharmaceutical compositions are useful for treating inflammatory conditions and autoimmune diseases associated with Th17 cell mediated pathology.
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- Method And Compositions For Improving Selective Catabolysis And Viability In Cells Of Keratin Surfaces
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A composition for treating keratin surfaces to stimulate selective catabolysis and improve cellular viability comprising at least one autophagy activator and at least one DNA repair enzyme, and a method for improving selective catabolysis and cellular viability by treating with the composition.
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- TREATMENT OF HEART DISEASE BY INHIBITION OF THE ACTION OF RIBOSOMAL S6 KINASE 3 (RSK3)
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The present invention provides a method of protecting the heart from damage, by administering to a patient at risk of such damage, a pharmaceutically effective amount of a composition which inhibits the interaction of RSK3 and mAKAPβ, or the expression or activity of one or both of those molecules. This composition may be in the form of a peptide that specifically inhibits mAKAPβ binding to RSK3 or in the form of an siRNA construct which inhibits the expression of RSK3.
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- Immunomodulatory peptides
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The invention relates to peptides derivatized with a hydrophilic polymer which, in some embodiments, bind to human FcRn and inhibit binding of the Fc portion of an IgG to an FcRn, thereby modulating serum IgG levels. The disclosed compositions and methods may be used in some embodiments, for example, in treating autoimmune diseases and inflammatory disorders. The invention also relates, in further embodiments, to methods of using and methods of making the peptides of the invention.
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- A role for glutamate-333 of Saccharomyces cerevisiae cystathionine γ-lyase as a determinant of specificity
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Cystathionine γ-lyase (CGL) catalyzes the hydrolysis of l-cystathionine (l-Cth), producing l-cysteine (l-Cys), α-ketobutyrate and ammonia, in the second step of the reverse transsulfuration pathway, which converts l-homocysteine (l-Hcys) to l-Cys. Site-directed variants substituting residues E48 and E333 with alanine, aspartate and glutamine were characterized to probe the roles of these acidic residues, conserved in fungal and mammalian CGL sequences, in the active-site of CGL from Saccharomyces cerevisiae (yCGL). The pH optimum of variants containing the alanine or glutamine substitutions of E333 is increased by 0.4-1.2 pH units, likely due to repositioning of the cofactor and modification of the pKa of the pyridinium nitrogen. The pH profile of yCGL-E48A/E333A resembles that of Escherichia coli cystathionine β-lyase. The effect of substituting E48, E333 or both residues is the 1.3-3, 26-58 and 124-568-fold reduction, respectively, of the catalytic efficiency of l-Cth hydrolysis. The Kml-Cth of E333 substitution variants is increased ~ 17-fold, while Km l-OAS is within 2.5-fold of the wild-type enzyme, indicating that residue E333 interacts with the distal amine moiety of l-Cth, which is not present in the alternative substrate O-acetyl-l-serine. The catalytic efficiency of yCGL for α,γ-elimination of O-succinyl-l-homoserine (k cat/Kml-OSHS = 7 ± 2), which possesses a distal carboxylate, but lacks an amino group, is 300-fold lower than that of the physiological l-Cth substrate (kcat/Kml-Cth = 2100 ± 100) and 260-fold higher than that of l-Hcys (k cat/Kml-Hcys = 0.027 ± 0.005), which lacks both distal polar moieties. The results of this study suggest that the glutamate residue at position 333 is a determinant of specificity.
- Hopwood, Emily M.S.,Ahmed, Duale,Aitken, Susan M.
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p. 465 - 472
(2014/01/17)
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- SEPARATING AGENT AND MANUFACTURING METHOD THEREOF
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An embodiment of the present invention is a separating agent wherein a group represented by a chemical formula of: or a group represented by a chemical formula of: is introduced on a surface thereof.
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Paragraph 0067; 0068; 0069; 0070; 0071; 0072; 0107; 0108
(2015/01/07)
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- Cystine Diamide Analogs for the Prevention of Cystine Stone Formation in Cystinuria
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Cystine analogs that improve the solubility of L-cystine in urine for treatment of cystinuria and which have the structure: and pharmaceutically acceptable salts, solvates and prodrugs thereof, wherein each R and R′ pair are independently selected from (i) or (ii);(i) R and R′ are independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alcohol, substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclic, and substituted or unsubstituted heteroaryl, or(ii) R and R′ together form a substituted or unsubstituted heterocyclic ring structure, or a substituted or unsubstituted heteroaryl ring structure;X is hydrogen, or an alkyl; and Y is O or S.
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Paragraph 0120-0122
(2014/07/08)
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- Frenolicins C-G, Pyranonaphthoquinones from streptomyces sp. RM-4-15
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Appalachian active coal fire sites were selected for the isolation of bacterial strains belonging to the class actinobacteria. A comparison of high-resolution electrospray ionization mass spectrometry (HRESIMS) and ultraviolet (UV) absorption profiles from isolate extracts to natural product databases suggested Streptomyces sp. RM-4-15 to produce unique metabolites. Four new pyranonaphthoquinones, frenolicins C-F (1-4), along with three known analogues, frenolicin (6), frenolicin B (7), and UCF76-A (8), were isolated from the fermentation of this strain. An additional new analogue, frenolicin G (5), along with two known compounds, deoxyfrenolicin (9) and UCF 13 (10), were isolated from the fermentation supplied with 18 mg/L of scandium chloride, the first example, to the best of our knowledge, wherein scandium chloride supplementation led to the confirmed production of new bacterial secondary metabolites. Structures 1-5 were elucidated on the basis of spectral analysis and chemical modification. While frenolicins are best known for their anticoccidial activity, the current study revealed compounds 6-9 to exhibit moderate cytotoxicity against the human lung carcinoma cell line (A549) and thereby extends the anticancer SAR for this privileged scaffold.
- Wang, Xiachang,Shaaban, Khaled A.,Elshahawi, Sherif I.,Ponomareva, Larissa V.,Sunkara, Manjula,Zhang, Yinan,Copley, Gregory C.,Hower, James C.,Morris, Andrew J.,Kharel, Madan K.,Thorson, Jon S.
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p. 1441 - 1447
(2013/09/23)
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- Establishment of an in vitro D-cycloserine-synthesizing system by using O-ureido-L-serine synthase and D-cycloserine synthetase found in the biosynthetic pathway
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We have recently cloned a DNA fragment containing a gene cluster that is responsible for the biosynthesis of an antituberculosis antibiotic, D-cycloserine. The gene cluster is composed of 10 open reading frames, designated dcsA to dcsJ. Judging from the sequence similarity between each putative gene product and known proteins, DcsC, which displays high homology to diaminopimelate epimerase, may catalyze the racemization of O-ureidoserine. DcsD is similar to O-acetylserine sulfhydrylase, which generates L-cysteine using O-acetyl-L-serine with sulfide, and therefore, DcsD may be a synthase to generate O-ureido-L-serine using O-acetyl-L-serine and hydroxyurea. DcsG, which exhibits similarity to a family of enzymes with an ATP-grasp fold, may be an ATP-dependent synthetase converting O-ureido-D-serine into D-cycloserine. In the present study, to characterize the enzymatic functions of DcsC, DcsD, and DcsG, each protein was overexpressed in Escherichia coli and purified to near homogeneity. The biochemical function of each of the reactions catalyzed by these three proteins was verified by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and, in some cases, mass spectrometry. The results from this study demonstrate that by using a mixture of the three purified enzymes and the two commercially available substrates O-acetyl-L-serine and hydroxyurea, synthesis of D-cycloserine was successfully attained. These in vitro studies yield the conclusion that DcsD and DcsG are necessary for the syntheses of O-ureido-L-serine and D-cycloserine, respectively. DcsD was also able to catalyze the synthesis of L-cysteine when sulfide was added instead of hydroxyurea. Furthermore, the present study shows that DcsG can also form other cyclic D-amino acid analogs, such as D-homocysteine thiolactone. Copyright
- Uda, Narutoshi,Matoba, Yasuyuki,Kumagai, Takanori,Oda, Kosuke,Noda, Masafumi,Sugiyama, Masanori
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supporting information
p. 2603 - 2612
(2013/07/28)
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- SEPARATING AGENT FOR CHROMATOGRAPHY
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A separating agent for chromatography is provided that is useful for the separation of specific compounds, e.g., for the optical resolution of amino acids. This separating agent for chromatography provides a higher productivity and contains a crown ether-like cyclic structure and optically active binaphthyl. This separating agent for chromatography containing a crown ether-like cyclic structure and optically active binaphthyl is provided by introducing a substitution group for binding to carrier into a specific commercially available 1,1′-binaphthyl derivative that has substituents at the 2, 2′, 3, and 3′ positions, then introducing a crown ether-like cyclic structure, and subsequently chemically bonding the binaphthyl derivative to the carrier through the substitution group for binding to carrier.
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Paragraph 0074; 0075
(2013/08/15)
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- Using the 9-BBN group as a transient protective group for the functionalization of reactive chains of α-amino acids
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Achieving chemoselectivity is a longstanding challenge in chemical synthesis. This problem has been addressed using different approaches, but a definitive solution is still pending. For instance, in peptide chemistry, particularly with amino acids containing side chains functionalities with reactivity patterns similar to the main functional groups, such as aspartic and glutamic acids, and lysine and ornithine, specific semi-permanent protecting groups have been employed. The use of 9-borabicyclo[3.3.1]nonane (9-BBN-H) as a transient protective group for the selective protection of α-amino acids, which allows the chemoselective manipulation of the functional groups embedded in the side chains of the molecule, is described.
- Sanchez, Adrian,Calderon, Ernesto,Vazquez, Alfredo
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p. 1364 - 1372
(2013/07/05)
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- MULTIMER GLYCOSYLATED NUCLEIC ACID BINDING PROTEIN CONJUGATES AND USES THEREOF
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The technology relates in part to multimer conjugates comprising a scaffold linked to two or more polypeptides that specifically interact with a nucleic acid containing beta-D-glucosyl-hydroxymethylcytosine or beta-D-glucosyl-hydroxymethyluracil. The scaffold can be chosen from an antibody, an antibody fragment, a multimerized binding partner that interacts with a binding partner counterpart in each of the polypeptides, a polymer, and a polyfunctional molecule. The polypeptides can be from a kinetoplastid flagellate organism and may comprise a full-length native or modified protein or a fragment thereof that specifically interacts with the beta-D-glucosyl-hydroxymethylcytosine and/or the beta-D-glucosyl-hydroxymethyluracil in the nucleic acid. The conjugates provided herein can be used to detect the presence, absence or amount of beta-D-glucosyl-hydroxymethylcytosine and/or beta-D-glucosyl-hydroxymethyluracil-containing nucleic acid in a sample.
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- Aminoacylase 1-catalysed deacetylation of bioactives epoxides mycotoxin-derived mercapturates; 3,4-epoxyprecocenes as models of cytotoxic epoxides
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The mycotoxin aflatoxin B1 (AFB1) is a carcinogenic food contaminant which is metabolically activated by epoxydation. The metabolism of mycotoxins via the mercapturate metabolic pathway was shown, in general, to lead to their detoxication. Mercapturic acids thus formed (S-substitued-N-acetyl-l-cysteines) may be accumulated in the kidney and either excreted in the urine or desacetylated by Acylase 1 (ACY1) to yield cysteine S-conjugates. To be toxic, the N-acetyl-l-cysteine-S-conjugates first have to undergo deacetylation by ACY 1. The specificity and rate of mercapturic acid deacetylation may determine the toxicity, however the exact deacetylation processes involved are not well known. The aim of this study was to investigate the role of ACY1 in the toxicity of some bioactive epoxides from Aflatoxin B1. We characterized the kinetic parameters of porcine kidney and human recombinant aminoacylase-1 towards some aromatic and aliphatic-derived mercapturates analogue of mycotoxin-mercapturic acids and 3,4-epoxyprecocene, a bioactive epoxide derivated from aflatoxin. The deacetylation of mercapturated substrates was followed both by reverse phase HPLC and by TNBS method. Catalytic activity was discussed in a structure-function relationship. Ours results indicate for the first time that aminoacylase-1 could play an important role in deacetylating mercapturate metabolites of aflatoxin analogues and this process may be in relation with their cyto- and nephrotoxicity in human.
- Stocker, Pierre,Brunel, Jean Michel,De Rezende, Leandro,-Do Amaral, Antonia Tavares,Morelli, Xavier,Roche, Phillipe,Vidal, Nicolas,Giardina, Thierry,Perrier, Josette
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experimental part
p. 1668 - 1675
(2012/08/29)
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- PTEN PHOSPHORYLATION-DRIVEN RESISTANCE TO CANCER TREATMENT AND ALTERED PATIENT PROGNOSIS
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Indicators that can guide clinical decisions in cancer, particularly posttranslational modification of proteins which result in altered prognosis and differential sensitivity to targeted cancer therapy, are provided. In particular, monitoring of phosphorylation of PTEN may be utilized to predict or assess drug response, drug sensitivity, and clinical outcome. Modulation of PTEN phosphorylation may be utilized to alter sensitivity and outcome in cancer patients. Posttranslational modification of PTEN, particularly phosphorylation, is correlated with resistance to targeted cancer therapy, including EGFR inhibitors, and with reduced survival prognosis. Methods and assays for determining phosphorylation of PTEN, particularly Y240 phosphorylation, are provided. Methods for sensitizing tumors to inhibition and targeted therapy by modulating PTEN phosphorylation are provided.
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- ANTIBODY MOLECULES WHICH BIND IL-17A AND IL-17F
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The invention relates to antibody molecules having specificity for antigenic determinants of both IL-17A and IL-17F, therapeutic uses of the antibody molecules and methods for producing said antibody molecules.
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- BINARY AND TERTIARY GALVANIC PARTICULATES AND METHODS OF MANUFACTURING AND USE THEREOF
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The present invention relates to galvanic particulates, their methods of manufacture and uses in treatments are described. The galvanic particulates may be binary or tertiary galvanic particulates, for example, containing multiple layers or phases of conductive materials.
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- Entamoeba histolytica thioredoxin reductase: Molecular and functional characterization of its atypical properties
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Background: Entamoeba histolytica, an intestinal protozoan that is the causative agent of amoebiasis, is exposed to elevated amounts of highly toxic reactive oxygen and nitrogen species during tissue invasion. Thioredoxin reductase catalyzes the reversible transfer of reducing equivalents between NADPH and thioredoxin, a small protein that plays key metabolic functions in maintaining the intracellular redox balance. Methods: The present work deals with in vitro steady state kinetic studies aimed to reach a better understanding of the kinetic and structural properties of thioredoxin reductase from E. histolytica (EhTRXR). Results: Our results support that native EhTRXR is a homodimeric covalent protein that is able to catalyze the NAD(P)H-dependent reduction of amoebic thioredoxins and S-nitrosothiols. In addition, the enzyme exhibited NAD(P)H dependent oxidase activity, which generates hydrogen peroxide from molecular oxygen. The enzyme can reduce compounds like methylene blue, quinones, ferricyanide or nitro-derivatives; all alternative substrates displaying a relative high capacity to inhibit disulfide reductase activity of EhTRXR. Conclusions and general significance: Interestingly, EhTRXR exhibited kinetic and structural properties that differ from other low molecular weight TRXR. The TRX system could play an important role in the parasite defense against reactive species. The latter should be critical during the extra intestinal phase of the amoebic infection. So far we know, this is the first in depth characterization of EhTRXR activity and functionality.
- Arias, Diego G.,Regner, Erika L.,Iglesias, Alberto A.,Guerrero, Sergio A.
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p. 1859 - 1866
(2013/01/15)
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- Peptide bond hydrolysis catalyzed by the Wells-Dawson Zr(α 2-P2W17O61)2 polyoxometalate
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In this paper we report the first example of peptide hydrolysis catalyzed by a polyoxometalate complex. A series of metal-substituted Wells-Dawson polyoxometalates were synthesized, and their hydrolytic activity toward the peptide bond in glycylglycine (GG) was examined. Among these, the Zr(IV)- and Hf(IV)-substituted ones were the most reactive. Detailed kinetic studies were performed with the Zr(IV)-substituted Wells-Dawson type polyoxometalate K 15H[Zr(α2-P2W17O 61)2]·25H2O which was shown to act as a catalyst for the hydrolysis of the peptide bond in GG. The speciation of K 15H[Zr(α2-P2W17O 61)2]·25H2O which is highly dependent on the pD, concentration, and temperature of the solution, was fully determined with the help of 31P NMR spectroscopy and its influence on the GG hydrolysis rate was examined. The highest reaction rate (kobs = 9.2 (±0.2) × 10-5 min-1) was observed at pD 5.0 and 60 °C. A 10-fold excess of GG was hydrolyzed in the presence of K 15H[Zr(α2-P2W17O 61)2]·25H2O proving the principles of catalysis. 13C NMR data suggested the coordination of GG to the Zr(IV) center in K15H[Zr(α2-P2W 17O61)2]·25H2O via its N-terminal amine group and amide carbonyl oxygen. These findings were confirmed by the inactivity of K15H[Zr(α2-P2W 17O61)2]·25H2O toward the N-blocked analogue acetamidoglycylglycinate and the inhibitory effect of oxalic, malic, and citric acid. Triglycine, tetraglycine, and pentaglycine were also fully hydrolyzed in the presence of K15H[Zr(α2- P2W17O61)2]·25H2O yielding glycine as the final product of hydrolysis. K15H[Zr(α 2-P2W17O61)2] ·25H2O also exhibited hydrolytic activity toward a series of other dipeptides.
- Absillis, Gregory,Parac-Vogt, Tatjana N.
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p. 9902 - 9910,9
(2012/12/11)
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