1263-76-9Relevant articles and documents
Expression, purification, and characterization of the maltooligosyltrehalose trehalohydrolase from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092
Fang, Tsuei-Yun,Tseng, Wen-Chi,Guo, Meng-Shin,Shih, Tong-Yuan,Hung, Xing-Guang
, p. 7105 - 7112 (2006)
The maltooligosyltrehalose trehalohydrolase (MTHase) mainly cleaves the α-1,4-glucosidic linkage next to the α-1,1-linked terminal disaccharide of maltooligosyltrehalose to produce trehalose and the maltooligosaccharide with lower molecular mass. In this study, the treZ gene encoding MTHase was PCR-cloned from Sulfolobus solfataricus ATCC 35092 and then expressed in Escherichia coli. A high yield of the active wild-type MTHase, 13300 units/g of wet cells, was obtained in the absence of IPTG induction. Wild-type MTHase was purified sequentially using heat treatment, nucleic acid precipitation, and ion-exchange chromatography. The purified wild-type MTHase showed an apparent optimal pH of 5 and an optimal temperature at 85°C. The enzyme was stable at pH values ranging from 3.5 to 11, and the activity was fully retained after a 2-h incubation at 45-85°C. The kcat values of the enzyme for hydrolysis of maltooligosyltrehaloses with degree of polymerization (DP) 4-7 were 193, 1030, 1190, and 1230 s-1, respectively, whereas the kcat values for glucose formation during hydrolysis of DP 4-7 maltooligosaccharides were 5.49, 17.7, 18.2, and 6.01 s-1, respectively. The KM values of the enzyme for hydrolysis of DP 4-7 maltooligosyltrehaloses and those for maltooligosaccharides are similar at the same corresponding DPs. These results suggest that this MTHase could be used to produce trehalose at high temperatures.
Structural and biochemical analyses of glycoside hydrolase families 5 and 26 β-(1,4)-mannanases from Podospora anserina reveal differences upon manno-oligosaccharide catalysis
Couturier, Marie,Roussel, Alain,Rosengren, Anna,Leone, Philippe,Stalbrand, Henrik,Berrin, Jean-Guy
, p. 14624 - 14635 (2013/07/28)
The microbial deconstruction of the plant cell wall is a key biological process that is of increasing importance with the development of a sustainable biofuel industry. The glycoside hydrolase families GH5 (PaMan5A) and GH26 (PaMan26A) endo-β-1,4-mannanases from the coprophilic ascomycete Podospora anserina contribute to the enzymatic degradation of lignocellulosic biomass. In this study, P. anserina mannanases were further subjected to detailed comparative analysis of their substrate specificities, active site organization, and transglycosylation capacity. Although PaMan5A displays a classical mode of action, PaMan26A revealed an atypical hydrolysis pattern with the release of mannotetraose and mannose from mannopentaose resulting from a predominant binding mode involving the -4 subsite. The crystal structures of PaMan5A and PaMan26A were solved at 1.4 and 2.85 A resolution, respectively. Analysis of the PaMan26A structure supported strong interaction with substrate at the -4 subsite mediated by two aromatic residues Trp-244 and Trp-245. The PaMan26A structure appended to its family 35 carbohydrate binding module revealed a short and proline-rich rigid linker that anchored together the catalytic and the binding modules.
Increased transglycosylation activity of Rhodotorula glutinis endo-β-glucanase in media containing organic solvent
Oikawa, Tadao,Tsukagawa, Yasuyuki,Chino, Masashi,Soda, Kenji
, p. 1889 - 1892 (2007/10/03)
The transglycosylation of p-nitrophenyl-β-D-cellotrioside to cellotetraose catalyzed by endo-1,4-β-glucanase (cellulase, EC 3.2.1.4) from a psychrotrophic yeast, Rhodotorula glutinis KUJ 2731, was increased by addition of a miscible organic solvent in the reaction mixture. Among various organic solvents tested, acetone was most effective. The transglycosylation activity increased with an increase in acetone concentrations, while hydrolysis activity was suppressed. The transglycosylation preferably occurred at acidic pH with the optimum pH at 2 in 10 mM Gly-HCl buffer. The optimum temperature of transglycosylation was found to be 50°C in the presence of 40% acetone.
