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The second nucleophile molecule binds to the acyl‐enzyme–nucleophile complex in α‐chymotrypsin catalysis : Kinetic evidence for the interaction

GOLOLOBOV, Mikhail Y. ; STEPANOV, Valentin M. ; VOYUSHINA, Tatjana L. and ADLERCREUTZ, Patrick LU (1993) In European Journal of Biochemistry 217(3). p.955-963
Abstract

α‐Chymotrypsin‐catalyzed acyl tranfer was studied using three acyl‐group donors (Mal‐l‐Ala‐l‐Ala‐l‐PheOMe, Bz‐l‐TyrOEt and Ac‐l‐TrpOEt; Mal, maleyl; Bz, benzoyl; OMe, methyl ester; OEt, ethyl ester) and a series of amino‐acid amides. Most of the reactions studied can be described by the simplest kinetic model without the nucleophile binding to the acyl‐enzyme. The α‐chymotrypsin‐catalyzed transfer of the Mal‐l‐Ala‐l‐Ala‐l‐Phe group to the amides of L‐Phe and L‐Tyr showed a linear dependence of the partition constant, p, on the nucleophile concentration which can be interpreted by the hydrolysis of the acyl‐enzyme–nucleophile complex. The α‐chymotrypsin‐catalyzed transfer of the Bz‐l‐Tyr and Ac‐l‐Trp groups to several amino‐acid amides... (More)

α‐Chymotrypsin‐catalyzed acyl tranfer was studied using three acyl‐group donors (Mal‐l‐Ala‐l‐Ala‐l‐PheOMe, Bz‐l‐TyrOEt and Ac‐l‐TrpOEt; Mal, maleyl; Bz, benzoyl; OMe, methyl ester; OEt, ethyl ester) and a series of amino‐acid amides. Most of the reactions studied can be described by the simplest kinetic model without the nucleophile binding to the acyl‐enzyme. The α‐chymotrypsin‐catalyzed transfer of the Mal‐l‐Ala‐l‐Ala‐l‐Phe group to the amides of L‐Phe and L‐Tyr showed a linear dependence of the partition constant, p, on the nucleophile concentration which can be interpreted by the hydrolysis of the acyl‐enzyme–nucleophile complex. The α‐chymotrypsin‐catalyzed transfer of the Bz‐l‐Tyr and Ac‐l‐Trp groups to several amino‐acid amides showed unusual behavior which can be interpreted by the kinetic model involving formation of a complex of the acyl‐enzyme with two nucleophile molecules. These observations can explain the conflicting conclusions concerning the kinetics of α‐chymotrypsin‐catalyzed acyl transfer evident in previous studies.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Journal of Biochemistry
volume
217
issue
3
pages
9 pages
publisher
Wiley-Blackwell
external identifiers
  • pmid:8223653
  • scopus:0027430154
ISSN
0014-2956
DOI
10.1111/j.1432-1033.1993.tb18326.x
language
English
LU publication?
yes
id
ea207b5d-4727-4717-a9ad-ec9e836cf4f4
date added to LUP
2019-06-22 09:20:30
date last changed
2020-01-13 02:04:59
@article{ea207b5d-4727-4717-a9ad-ec9e836cf4f4,
  abstract     = {<p>α‐Chymotrypsin‐catalyzed acyl tranfer was studied using three acyl‐group donors (Mal‐l‐Ala‐l‐Ala‐l‐PheOMe, Bz‐l‐TyrOEt and Ac‐l‐TrpOEt; Mal, maleyl; Bz, benzoyl; OMe, methyl ester; OEt, ethyl ester) and a series of amino‐acid amides. Most of the reactions studied can be described by the simplest kinetic model without the nucleophile binding to the acyl‐enzyme. The α‐chymotrypsin‐catalyzed transfer of the Mal‐l‐Ala‐l‐Ala‐l‐Phe group to the amides of L‐Phe and L‐Tyr showed a linear dependence of the partition constant, p, on the nucleophile concentration which can be interpreted by the hydrolysis of the acyl‐enzyme–nucleophile complex. The α‐chymotrypsin‐catalyzed transfer of the Bz‐l‐Tyr and Ac‐l‐Trp groups to several amino‐acid amides showed unusual behavior which can be interpreted by the kinetic model involving formation of a complex of the acyl‐enzyme with two nucleophile molecules. These observations can explain the conflicting conclusions concerning the kinetics of α‐chymotrypsin‐catalyzed acyl transfer evident in previous studies.</p>},
  author       = {GOLOLOBOV, Mikhail Y. and STEPANOV, Valentin M. and VOYUSHINA, Tatjana L. and ADLERCREUTZ, Patrick},
  issn         = {0014-2956},
  language     = {eng},
  month        = {01},
  number       = {3},
  pages        = {955--963},
  publisher    = {Wiley-Blackwell},
  series       = {European Journal of Biochemistry},
  title        = {The second nucleophile molecule binds to the acyl‐enzyme–nucleophile complex in α‐chymotrypsin catalysis : Kinetic evidence for the interaction},
  url          = {http://dx.doi.org/10.1111/j.1432-1033.1993.tb18326.x},
  doi          = {10.1111/j.1432-1033.1993.tb18326.x},
  volume       = {217},
  year         = {1993},
}