The Role of a Tyrosine Residue of Bacterial Liquefying α-Amylase in the Enzymatic Hydrolysis of Linear Substrates as Studied by Chemical Modification with Acetic Anhydride*

We report two different chemoenzymatic enantioselective syntheses of baclofen based on the distinction between enantiotopic ester groups in compounds bearing a prochiral centre. In the first approach, the key step is the highly stereoselective enzymatic hydrolysis of dimethyl 3-(4-chlorophenyl)glutarate by chymotrypsin in an aqueous medium. In the second approach, the key step is the enzyme-catalyzed esterification of 2-(4-chloropheny 1)-1,3-propanediol by acetic anhydride in the presence of a lipase in an organic medium.

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The Role of Tryptophan Residues of Bacterial Liquefying a-Amylase and Taka-amylase A in the Enzymatic Hydrolysis of Linear Substrates12

The Journal of Biochemistry ◽

10.1093/oxfordjournals.jbchem.a130356 ◽

1973 ◽

Vol 74 (6) ◽

pp. 1271-1273 ◽

Cited By ~ 7

Author(s):

Masatake OHNISHI ◽

Toshihiko SUGANUMA ◽

Haruko FUJIMORI ◽

Keitaro HIROMI

Keyword(s):

Enzymatic Hydrolysis ◽

Tryptophan Residues ◽

Hydrolysis Of

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Enzymatic Activity in the M Band

The Journal of Cell Biology ◽

10.1083/jcb.6.2.163 ◽

1959 ◽

Vol 6 (2) ◽

pp. 163-170 ◽

Cited By ~ 61

Author(s):

Russell J. Barrnett ◽

George E. Palade

Keyword(s):

Electron Microscopy ◽

Enzymatic Hydrolysis ◽

Enzymatic Activity ◽

Striated Muscles ◽

Histochemical Reaction ◽

Esterase Inhibitors ◽

Enzymatic Nature ◽

Hydrolysis Of ◽

Thiolacetic Acid

Experiments which combined histochemistry and electron microscopy were performed in studying the sites of enzymatic hydrolysis of thiolacetic acid in the presence of lead ions in diaphragmatic and cardiac muscle. It was found that in these striated muscles the electron opaque, final product of the histochemical reaction (PbS) was discretely deposited on the swelling of the thick elemental filaments that occurs at the M band. Additional sites of enzymatic activity occurred in mitrochondria and in round sarcoplasmic bodies. A reaction, probably non-enzymatic, also occurred in contraction bands in the area of the Z bands and in the sarcoplasmic reticulum. To ascertain the enzymatic nature of the reaction and to define the enzyme involved, control experiments were carried out and the effect of various esterase inhibitors was assayed. It is suggested that the M band enzyme is a cholinesterase, but the enzymes in the mitochondria and the sarcoplasmic bodies that hydrolyze the substrate appear to be different. A possible role of the M band enzyme is discussed.

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Role of bicontinuous microemulsion in the rapid enzymatic hydrolysis of (R,S)-ketoprofen ethyl ester in a micro-reactor

Bioresource Technology ◽

10.1016/j.biortech.2010.05.032 ◽

2010 ◽

Vol 101 (20) ◽

pp. 7834-7840 ◽

Cited By ~ 19

Author(s):

M. Sathishkumar ◽

R. Jayabalan ◽

S.P. Mun ◽

S.E. Yun

Keyword(s):

Enzymatic Hydrolysis ◽

Ethyl Ester ◽

Bicontinuous Microemulsion ◽

Hydrolysis Of ◽

Micro Reactor

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The role of acetyl xylan esterase in the solubilization of xylan and enzymatic hydrolysis of wheat straw and giant reed

Biotechnology for Biofuels ◽

10.1186/1754-6834-4-60 ◽

2011 ◽

Vol 4 (1) ◽

pp. 60 ◽

Cited By ~ 83

Author(s):

Junhua Zhang ◽

Matti Siika-aho ◽

Maija Tenkanen ◽

Liisa Viikari

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Giant Reed ◽

Acetyl Xylan Esterase ◽

Hydrolysis Of

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Preparation of N-Acetylchitooligosaccharides by Enzymatic Hydrolysis of Chitosans

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.160-162.1358 ◽

2010 ◽

Vol 160-162 ◽

pp. 1358-1361

Author(s):

Hong Zhu ◽

Zhi Hui Qiu ◽

Qiong Hou

Keyword(s):

Enzymatic Hydrolysis ◽

Aspergillus Niger ◽

Acetic Anhydride ◽

Production Process ◽

Chemical Reactions ◽

Enzyme Preparations ◽

High Yields ◽

Hydrolysis Of

An economical production process of higher N-acetylchitooligosaccharides [(GlcNAc)n, n=5~7 ] was developed with enzymatic and chemical reactions in this study. (GlcNAc)n were prepared selectively and efficiently by hydrolysis of chitosans with cheap enzyme preparations including cellulase TV, cellulosin A.C and hemicellulase, followed by N-acetylation with acetic anhydride. Higher (GlcNAc)n could be obtained in high yields by using cellulosin A.C and hemicellulase, which are originated from Aspergillus niger.

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