Enzymes as synthetic catalysts: mechanistic and active-site considerations of natural and modified chymotrypsin

This paper describes the mechanistic investigation of {alpha}-chymotrypsin and (Met{sub 192}-sulfoxide)-{alpha}-chymotrypsin-catalyzed peptide synthesis in a kinetically controlled process (i.e., aminolysis) and the relative stabilities of both enzymes in different conditions. Partitioning parameter...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 1990-06, Vol.112 (13), p.5313-5320
Main Authors: West, J. Blair, Hennen, William J, Lalonde, James L, Bibbs, Jeffrey A, Zhong, Ziyang, Meyer, Edgar F, Wong, Chi Huey
Format: Article
Language:English
Subjects:
BASIC BIOLOGICAL SCIENCES
CATALYSTS
CHYMOTRYPSIN
DATA
DATA ANALYSIS
ENZYMES
EXPERIMENTAL DATA
FUNCTIONS
HYDROLASES
INFORMATION
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
PARTITION FUNCTIONS
PEPTIDE HYDROLASES
PEPTIDES
PROTEINS
SERINE PROTEINASES 550200 > Biochemistry
SYNTHESIS
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper describes the mechanistic investigation of {alpha}-chymotrypsin and (Met{sub 192}-sulfoxide)-{alpha}-chymotrypsin-catalyzed peptide synthesis in a kinetically controlled process (i.e., aminolysis) and the relative stabilities of both enzymes in different conditions. Partitioning parameters for various nucleophiles (including D- and L-amino acids) competing with water for the acyl enzyme intermediate were determined. these parameters provide insights into the active-site geometries of both the native and the oxidized enzymes. {alpha}-Chymotrypsin with D-isomer selectivity in the hydrolysis of {alpha}-methyl-{alpha}-nitro esters was used for the synthesis of a D-L pseudopeptide. Molecular modeling together with kinetic results was used to explain the unusual phenomena in hydrolysis and synthesis catalyzed by the native and modified enzymes. {alpha}-Chymotrypsin methylated at the {epsilon}{sub 2}-N of the active-site histidine was shown to be an effective catalyst for peptide synthesis in the kinetically controlled process. No peptide bond hydrolysis was observed.
ISSN:0002-7863
1520-5126
DOI:10.1021/ja00169a043