Document Detail


Kinetic anomalies in chymotryptic hydrolyses of p-nitrophenyl acetate and N-benzoyl-L-alanine methyl ester.
MedLine Citation:
PMID:  2805158     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Kinetic and thermodynamic parameters were evaluated for the acylation and the deacylation steps in the hydrolysis of p-nitrophenyl acetate by alpha-chymotrypsin at pH 7.8 and at temperatures between 15 and 35 degrees C by the use of stopped-flow and ordinary ultraviolet spectrophotometers. In contrast to the temperature dependencies of k2 and Ks reported in the literature (P.A. Adams and E.R. Swart, Biochem. J., 161, 83 (1977], no kinetic anomaly was observed in either of the steps, but reasonable straight lines were obtained in both Arrhenius and van't Hoff plots. On the other hand, in the chymotryptic hydrolysis of N-benzoyl-L-alanine methyl ester a sharp kinetic anomaly was found. The discrepancy in the case of p-nitrophenyl acetate is discussed in connection with a possible conformational change of the enzyme, an alteration of the rate-limiting step or differences in the experimental procedures. The cause of the anomaly observed in the case of N-benzoyl-L-alanine methyl ester is also discussed in detail.
Authors:
D Nohara; M Wakamatsu; M Goto; T Sakai
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Chemical & pharmaceutical bulletin     Volume:  37     ISSN:  0009-2363     ISO Abbreviation:  Chem. Pharm. Bull.     Publication Date:  1989 Jul 
Date Detail:
Created Date:  1989-12-12     Completed Date:  1989-12-12     Revised Date:  2000-12-18    
Medline Journal Info:
Nlm Unique ID:  0377775     Medline TA:  Chem Pharm Bull (Tokyo)     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  1685-90     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Alanine / pharmacokinetics
Chymotrypsin
Hydrolysis
Nitrophenols / pharmacokinetics*
Thermodynamics
Chemical
Reg. No./Substance:
0/Nitrophenols; 56-41-7/Alanine; 7244-67-9/N-benzoylalanine methyl ester; 830-03-5/4-nitrophenyl acetate; EC 3.4.21.1/Chymotrypsin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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