- Semi-rational hinge engineering: modulating the conformational transformation of glutamate dehydrogenase for enhanced reductive amination activity towards non-natural substrates
-
The active site is the common hotspot for rational and semi-rational enzyme activity engineering. However, the active site represents only a small portion of the whole enzyme. Identifying more hotspots other than the active site for enzyme activity engineering should aid in the development of biocatalysts with better catalytic performance. Glutamate dehydrogenases (GluDHs) are promising and environmentally benign biocatalysts for the synthesis of valuable chirall-amino acids by asymmetric reductive amination of α-keto acids. GluDHs contain an inter-domain hinge structure that facilitates dynamic reorientations of the domains relative to each other. Such hinge-bending conformational motions of GluDHs play an important role in regulating the catalytic activity. Thus, the hinge region represents a potential hotspot for catalytic activity engineering for GluDHs. Herein, we report semi-rational activity engineering of GluDHs with the hinge region as the hotspot. Mutants exhibiting significantly improved catalytic activity toward several non-natural substrates were identified and the highest activity increase reached 104-fold. Molecular dynamics simulations revealed that enhanced catalytic activity may arise from improving the open/closed conformational transformation efficiency of the protein with hinge engineering. In the batch production of three valuablel-amino acids, the mutants exhibited significantly improved catalytic efficiency, highlighting their industrial potential. Moreover, the catalytic activity of several active site tailored GluDHs was also increased by hinge engineering, indicating that hinge and active site engineering are compatible. The results show that the hinge region is a promising hotspot for activity engineering of GluDHs and provides a potent alternative for developing high-performance biocatalysts toward chirall-amino acid production.
- Liu, Yayun,Meng, Lijun,Wu, Jianping,Yang, Lirong,Yin, Xinjian,Zhou, Haisheng
-
p. 3376 - 3386
(2020/06/09)
-
- Preparative Asymmetric Synthesis of Canonical and Non-canonical a-amino Acids through Formal Enantioselective Biocatalytic Amination of Carboxylic Acids
-
Chemical and biocatalytic synthesis of non-canonical a-amino acids (ncAAs) from renewable feedstocks and using mild reaction conditions has not efficiently been solved. Here, we show the development of a three-step, scalable and modular one-pot biocascade for linear conversion of renewable fatty acids (FAs) into enantiopure l-a-amino acids. In module 1, selective a-hydroxylation of FAs is catalyzed by the P450 peroxygenase P450CLA. By using an automated H2O2 supplementation system, efficient conversion (46 to >99%; TTN>3300) of a broad range of FAs (C6:0 to C16:0) into valuable a-hydroxy acids (a-HAs; >90% a-selective) is shown on preparative scale (up to 2.3 gL1 isolated product). In module 2, a redox-neutral hydrogen borrowing cascade (alcohol dehydrogenase/amino acid dehydrogenase) allowed further conversion of a-HAs into l-a-AAs (20 to 99%). Enantiopure l-a-AAs (e.e. >99%) including the pharma synthon l-homo-phenylalanine can be obtained at product titers of up to 2.5 gL1. Based on renewables and excellent atom economy, this biocascade is among the shortest and greenest synthetic routes to structurally diverse and industrially relevant ncAAs.
- Dennig, Alexander,Blaschke, Fabio,Gandomkar, Somayyeh,Tassano, Erika,Nidetzky, Bernd
-
supporting information
p. 1348 - 1358
(2019/10/28)
-
- Two novel cyclic depsipeptides Xenematides F and G from the entomopathogenic bacterium Xenorhabdus budapestensis
-
Two novel depsipeptides xenematides F and G (1, 2), were isolated from entomopathogenic Xenorhabdus budapestensis SN84 along with a known compound xenematide B. The structures of the two new molecules were elucidated using NMR, MS and Marfey’s method. The xenematide G (2) contains α-aminoheptanoic acid, a non-protein amino acid that is rarely found in secondary metabolites from entomopathogenic bacteria. Xenematides F and G were tested for antibacterial activity. Xenematide G (2) exhibited moderate antibacterial activity.
- Xi, Xuedong,Lu, Xingzhong,Zhang, Xiaodong,Bi, Yuhui,Li, Xiaochun,Yu, Zhiguo
-
-
- Preparative Asymmetric Synthesis of Canonical and Non-canonical α-amino Acids Through Formal Enantioselective Biocatalytic Amination of Carboxylic Acids
-
Chemical and biocatalytic synthesis of non-canonical α-amino acids (ncAAs) from renewable feedstocks and using mild reaction conditions has not efficiently been solved. Here, we show the development of a three-step, scalable and modular one-pot biocascade for linear conversion of renewable fatty acids (FAs) into enantiopure l-α-amino acids. In module 1, selective α-hydroxylation of FAs is catalyzed by the P450 peroxygenase P450CLA. By using an automated H2O2 supplementation system, efficient conversion (46 to >99%; TTN>3300) of a broad range of FAs (C6:0 to C16:0) into valuable α-hydroxy acids (α-HAs; >90% α-selective) is shown on preparative scale (up to 2.3 g L?1 isolated product). In module 2, a redox-neutral hydrogen borrowing cascade (alcohol dehydrogenase/amino acid dehydrogenase) allowed further conversion of α-HAs into l-α-AAs (20 to 99%). Enantiopure l-α-AAs (e.e. >99%) including the pharma synthon l-homo-phenylalanine can be obtained at product titers of up to 2.5 g L?1. Based on renewables and excellent atom economy, this biocascade is among the shortest and greenest synthetic routes to structurally diverse and industrially relevant ncAAs. (Figure presented.).
- Dennig, Alexander,Blaschke, Fabio,Gandomkar, Somayyeh,Tassano, Erika,Nidetzky, Bernd
-
supporting information
(2019/02/09)
-
- Asymmetric synthesis of aliphatic α-amino and γ-hydroxy α-amino acids and introduction of a template for crystallization-induced asymmetric transformation
-
The asymmetric synthesis of aliphatic α-amino and γ-hydroxy α-amino acids is described. The key step is an aza-Michael addition controlled by crystallization-induced asymmetric transformation (CIAT), affording excellent diastereomeric ratios (dr ≥96:4). C
- Jakubec, Pavol,Berkes, Dusan,Kolarovic, Andrej,Povazanec, Frantisek
-
p. 4032 - 4040
(2008/03/11)
-
- Synthesis of α-amino acids by reaction of aziridine-2-carboxylic acids with carbon nucleophiles
-
A variety of homochiral α-amino acids have been prepared in good yield via regioselective reaction of higher order cuprates with (2S)-N-para-toluenesulfonylaziridine-2-carboxylic acid 4. The reaction was much less regioselective and low yielding when higher order cuprates were reacted with the more hindered aziridine carboxylic acid 30, the principal products being protected β-amino acids. Reaction of lithium trimethylsilylacetylide with the aziridine acid 30, however, gave a protected α-amino acid which was converted to the protected isoleucine ester 37. The Royal Society of Chemistry 2006.
- Beresford, Kenneth J. M.,Church, Nicola J.,Young, Douglas W.
-
p. 2888 - 2897
(2008/02/08)
-
- Resolution of non-protein amino acids via the microbial protease-catalyzed enantioselective hydrolysis of their N-unprotected esters
-
In the Aspergillus oryzae protease-catalyzed ester hydrolysis, substitution of N-unprotected amino acid esters for the corresponding N-protected amino acid esters resulted in a large enhancement of the hydrolysis rate, while the enantioselectivity was deteriorated strikingly when the substrates employed were the conventional methyl esters. This difficulty was overcome by employing esters bearing a longer alkyl chain such as the isobutyl ester. Utilizing this ester, amino acids carrying an aromatic side chain were resolved with excellent enantioselectivities (E=50 to >200). With amino acids bearing an aliphatic side chain also, good results in terms of the hydrolysis rate and enantioselectivity were obtained by employing such an ester as the isobutyl ester. Moreover, the enantioselectivity proved to be enhanced further by conducting the reaction at low temperature. This procedure was applicable to the case where the enantioselectivity was not high enough even by the use of the isobutyl ester.
- Miyazawa, Toshifumi,Imagawa, Kiwamu,Minowa, Hiroe,Miyamoto, Toyoko,Yamada, Takashi
-
p. 10254 - 10261
(2007/10/03)
-
- Resolution of non-protein amino acids via microbial protease-catalyzed ester hydrolysis: Marked enhancement of enantioselectivity by the use of esters with longer alkyl chains and at low temperature
-
In the microbial protease-catalyzed hydrolysis of amino acid esters with the free α-amino group, the enantioselectivity can be enhanced greatly by employing esters with longer alkyl chains such as the isobutyl ester instead of the conventional methyl ester and by conducting the reaction at low temperature.
- Miyazawa, Toshifumi,Minowa, Hiroe,Miyamoto, Toyoko,Imagawa, Kiwamu,Yanagihara, Ryoji,Yamada, Takashi
-
p. 367 - 370
(2007/10/03)
-
- Synthesis of α-Amino Acids by Ring Opening of Aziridine-2-carboxylates with Carbon Nucleophiles
-
Excellent regiospecificity has been achieved in the reaction of carbon nucleophiles with N-para-toluenesulfonylaziridine-2-carboxylic acid (6, R=H) protected as the anion.This has been developed into a general and high yielding synthesis of optically pure α-amino acids containing one chiral centre.When the aziridine (20) containing a second chiral centre was used, only lithium trimethylsilylacetylide gave the desired α-amino acid.Reaction with higher order cuprates gave lower yields, the principal products being the protected β-amino acids (22) and (23).
- Church, Nicola J.,Young, Douglas W.
-
p. 151 - 154
(2007/10/02)
-
- Amino Acid Synthesis via Ring Opening of N-Sulphonyl Aziridine-2-Carboxylate Esters with Organometallic Reagents.
-
Nucleophilic ring opening of optically active N-sulphonyl aziridine-2-carboxylate esters with organometallic reagents has been investigated as a method of preparation of optically active amino acids.Key Words: aziridine-2-carboxylate, cuprate, nucleophilic ring opening, amino acid
- Baldwin, Jack E.,Spivey, Alan C.,Schofield, Christopher J.,Sweeney, Joseph B.
-
p. 6309 - 6330
(2007/10/02)
-
- The Ring Opening of Aziridine-2-carboxylate Esters with Organometallic Reagents
-
The ring opening of aziridines with organocuprate reagents provides a new entry to amino acids.
- Baldwin, Jack E.,Adlington, Robert M.,O'Neil, Ian A.,Schofield, Christopher,Spivey, Alan C.,Sweeney, Joseph B.
-
p. 1852 - 1854
(2007/10/02)
-
- Conversion of Serine β-Lactones to Chiral α-Amino Acids by Copper-Containing Organolithium and Organomagnesium Reagents
-
A method for the synthesis of optically pure α-amino acids has been developed.Mono- and di-N-protected α-amino-β-lactones 3a (L, R1=H, R2=COOCH2Ph (Z)), 3b (D, R1=H, R2=Z), 3c (L, R1=CH2Ph, R2=Z), and 3d (D, R1=CH2Ph, R2=Z) are readily produced by cyclization of the corresponding serine derivatives 2 under modified Mitsunobu conditions without loss of optical purity.Stereochemical integrity was demonstrated by conversion of 3 to 2-methoxy-2-(trifluoromethyl)phenylacetate esters 6 and analysis by HPLC, (19)F NMR, and (1)H NMR.Reaction of 3 with organolithium-derived cuprate reagents (R2CuLi or R2Cu(CN)Li2) at low temperature produces N-protected α-amino acids by attack at the β-methylene group.Yields of di-N-protected amino acids are generally higher (ca. 50-75percent), but some decrease in enantiomeric excess (ee) can occur (0-27percent).In contrast, the mono-N-protected β-lactones 3a and 3b give slightly lower yields (ca. 44-62percent) but negligible decrease in ee (0-1.7percent) with the exception of Ph2Cu(CN)Li2 (67percent loss of ee).However, the use of Cu(I)-catalyzed Grignard (RMgCl) additions gives better yields (44-83percent), complete retention of optical purity ( 99.4percent), and fewer side products.Reductive removal of the protecting groups in a single step (H2/Pd-C or Na/NH3) affords the free α-amino acids in 91-99percent yield.Their stereochemical purity was determined by conversion to the corresponding N-(-)-camphanoyl methyl esters and analysis by gas chromatography and (1)H NMR spectroscopy.
- Arnold, Lee D.,Drover, John C. G.,Vederas, John C.
-
p. 4649 - 4659
(2007/10/02)
-