Heterometallic PdII–Cl–CuI Catalyst for Efficient Hydrolysis of β-1,4-Glycosidic Bonds in 1-Butyl-3-methylimidazolium Chloride

ACS Catalysis ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 11774-11785
Author(s):  
Yiwen Yang ◽  
Haifeng Qi ◽  
Huixiang Li ◽  
Zhanwei Xu ◽  
Xiumei Liu ◽  
...  
Keyword(s):  
Glycosidic Bonds ◽  
Hydrolysis Of

scholarly journals Structural and Catalytic Characterization of TsBGL, a β-Glucosidase From Thermofilum sp. ex4484_79

2021 ◽  
Vol 12 ◽  
Author(s):  
Anke Chen ◽  
Dan Wang ◽  
Rui Ji ◽  
Jixi Li ◽  
Shaohua Gu ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Specific Activity ◽  
Maximum Activity ◽  
Homologous Proteins ◽  
Glycosidic Bonds ◽  
Catalytic Sites ◽  
Potential Applications ◽  
Beta Glucosidase ◽  
Hydrolysis Of

Beta-glucosidase is an enzyme that catalyzes the hydrolysis of the glycosidic bonds of cellobiose, resulting in the production of glucose, which is an important step for the effective utilization of cellulose. In the present study, a thermostable β-glucosidase was isolated and purified from the Thermoprotei Thermofilum sp. ex4484_79 and subjected to enzymatic and structural characterization. The purified β-glucosidase (TsBGL) exhibited maximum activity at 90°C and pH 5.0 and displayed maximum specific activity of 139.2μmol/min/mgzne against p-nitrophenyl β-D-glucopyranoside (pNPGlc) and 24.3μmol/min/mgzen against cellobiose. Furthermore, TsBGL exhibited a relatively high thermostability, retaining 84 and 47% of its activity after incubation at 85°C for 1.5h and 90°C for 1.5h, respectively. The crystal structure of TsBGL was resolved at a resolution of 2.14Å, which revealed a classical (α/β)8-barrel catalytic domain. A structural comparison of TsBGL with other homologous proteins revealed that its catalytic sites included Glu210 and Glu414. We provide the molecular structure of TsBGL and the possibility of improving its characteristics for potential applications in industries.

Acid Hydrolysis of Glycosidic Bonds in Polysaccharides: Modelling and Stochastic Simulation

1993 ◽  
pp. 1583-1597 ◽  
Author(s):  
José-Henrique Q. Pinto ◽  
Zin-Eddine Dadach ◽  
Alain Lemoyne ◽  
Serge Kaliaguine
Keyword(s):  
Acid Hydrolysis ◽  
Stochastic Simulation ◽  
Glycosidic Bonds ◽  
Hydrolysis Of

Efficient Hydrolytic Breakage of β-1,4-Glycosidic Bond Catalyzed by a Difunctional Magnetic Nanocatalyst

2018 ◽  
Vol 71 (8) ◽  
pp. 559 ◽  
Author(s):  
Ren-Qiang Yang ◽  
Ni Zhang ◽  
Xiang-Guang Meng ◽  
Xiao-Hong Liao ◽  
Lu Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Microcrystalline Cellulose ◽  
Significant Loss ◽  
Reducing Sugar ◽  
Magnetic Nanocatalyst ◽  
Efficient Catalyst ◽  
Glycosidic Bonds ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

A novel difunctional magnetic nanocatalyst (DMNC) was prepared and used to catalyse the hydrolytic breakage of β-1,4-glycosidic bonds. The functional nanoparticle displayed excellent catalytic activity for hydrolysis of cellobiose to glucose under moderate conditions. The conversion of cellobiose and yield of glucose could reach 95.3 and 91.1 %, respectively, for a reaction time of 6 h at pH 4.0 and 130°C. DMNC was also an efficient catalyst for the hydrolysis of cellulose: 53.9 % microcrystalline cellulose was hydrolyzed, and 45.7 % reducing sugar was obtained at pH 4.0 and 130°C after 10 h. The magnetic catalyst could be recycled and reused five times without significant loss of catalytic activity.

scholarly journals Preliminary X-ray diffraction analysis of a thermophilic β-1,3–1,4-glucanase fromClostridium thermocellum

2014 ◽  
Vol 70 (7) ◽  
pp. 946-948 ◽  
Author(s):  
Lilan Zhang ◽  
Puya Zhao ◽  
Chun-Chi Chen ◽  
Chun-Hsiang Huang ◽  
Tzu-Ping Ko ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Specific Activity ◽  
High Specific Activity ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Glycosidic Bonds ◽  
Hydrolysis Of

β-1,3–1,4-Glucanases catalyze the specific hydrolysis of internal β-1,4-glycosidic bonds adjacent to the 3-O-substituted glucose residues in mixed-linked β-glucans. The thermophilic glycoside hydrolase CtGlu16A fromClostridium thermocellumexhibits superior thermal profiles, high specific activity and broad pH adaptability. Here, the catalytic domain of CtGlu16A was expressed inEscherichia coli, purified and crystallized in the trigonal space groupP3121, with unit-cell parametersa=b= 74.5,c= 182.9 Å, by the sitting-drop vapour-diffusion method and diffracted to 1.95 Å resolution. The crystal contains two protein molecules in an asymmetric unit. Further structural determination and refinement are in progress.

ISOLATION AND PROPERTIES OF A GLUCOMANNAN FROM THE WOOD OF RED MAPLE (ACER RUBRUM L.)

1960 ◽  
Vol 38 (9) ◽  
pp. 1511-1517 ◽  
Author(s):  
A. Jabbar Mian ◽  
T. E. Timell
Keyword(s):  
Acer Rubrum ◽  
Partial Hydrolysis ◽  
Red Maple ◽  
Glycosidic Bonds ◽  
Linear Molecules ◽  
Hydrolysis Of

A glucomannan has been isolated from the wood of red maple (Acer rubrum L.) in a yield corresponding to 92% of the mannose residues in this wood and with a ratio of mannose to glucose of 2:1. Partial hydrolysis of the polysaccharide yielded 4-O-β-D-mannopyranosyl-D-mannose, 4-O-β-D-mannopyranosyl-D-glucose, 4-O-β-D-glucopyranosyl-D-mannose, 4-O-β-D-glucopyranosyl-D-glucose, and O-β-D-mannopyranosyl-(l → 4)-O-β-D-mannopyranosyl-(1 → 4)-D-mannose. The methylated glucomannan on hydrolysis gave a mixture of di-O-methylhexoses, 2,3,6-tri-O-methyl-D-mannose, 2,3,6-tri-O-methyl-D-glucose, and 2,3,4,6-tetra-O-methyl-D-glucose in a mole ratio of 7:29:13:1. The methylated polysaccharide contained 55 hexose residues per average molecule, while the corresponding value for the nitrate derivative was 67. It is concluded that the glucomannan is composed of a minimum of 70 glucose and mannose residues linked together by (1 → 4)-β-glycosidic bonds to linear molecules. The glucose residues are probably interposed between two or three contiguous mannose residues.

Anchimeric assistance in hexosaminidases

2002 ◽  
Vol 80 (8) ◽  
pp. 1064-1074 ◽  
Author(s):  
Brian L Mark ◽  
Michael NG James
Keyword(s):  
Oxygen Atom ◽  
Active Site ◽  
Sequence Similarity ◽  
Carbonyl Oxygen ◽  
Carbonyl Oxygen Atom ◽  
Carboxyl Groups ◽  
Displacement Mechanism ◽  
Glycosidic Bonds ◽  
Anchimeric Assistance ◽  
Hydrolysis Of

Configuration retaining glycosidases catalyse the hydrolysis of glycosidic bonds via a double displacement mechanism, typically involving two key active site carboxyl groups (Glu or Asp). One of the enzymic carboxyl groups functions as a general acid–base catalyst, the other acts as a nucleophile. Alternatively, configuration-retaining hexosaminidases from the sequence-related glycosidase families 18, 20, and 56 lack a suitably positioned enzymic nucleophile; instead, they use the carbonyl oxygen atom of the neighbouring C2-acetamido group of the substrate. The carbonyl oxygen atom of the 2-acetamido group provides anchimeric assistance to the enzyme catalyzed reaction by acting as an intramolecular nucleophile, attacking the anomeric center and forming a cyclized oxazolinium ion intermediate that is stereochemically equivalent to the glycosyl–enzyme intermediate formed in the "normal" double displacement mechanism. Although there is little sequence similarity between families 18, 20, and 56 hexosaminidases, X-ray crystallographic studies demonstrate that they have evolved similar catalytic domains and active site architectures that are designed to distort the bound substrate so that the C2-acetamido group can become appropriately positioned to participate in catalysis. The substrate distortion allows for a substrate-assisted catalytic reaction that displays all the general characteristics of the classic double-displacement mechanism including the formation of a covalent intermediate.Key words: glycoside hydrolase, hexosaminidase, glycosidase, substrate-assisted catalysis, anchimeric assistance.

Viscometric Determination of p-Glucanase and Endoxylanase Activity in Feed

1996 ◽  
Vol 79 (5) ◽  
pp. 1019-1025 ◽  
Author(s):  
Adrianus J Engelen ◽  
Fred C Van Der Heeft ◽  
Peter H G Randsdorp
Keyword(s):  
Enzymatic Activity ◽  
Standard Addition ◽  
Glycosidic Bonds ◽  
Hydrolysis Of ◽  
Feed Samples

Abstract A method is described for viscometric determination of enzymatic activity of β-glucanase and endoxylanase in feed samples. The method is based on determination of the decrease in viscosity as a result of hydrolysis of glycosidic bonds in β-glucan and xylan at pH 3.5. This method does not require a blank sample (feed without enzyme addition), and it does not need standard addition for reliable quantitation.

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