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Effects of subzero temperatures on the kinetics of protease catalyzed dipeptide synthesis in organic media

Jönsson, Åsa LU ; Adlercreutz, Patrick LU orcid and Mattiasson, Bo LU (1995) In Biotechnology and Bioengineering 46(5). p.429-436
Abstract

A depeptide synthesis was drastically influenced by the reaction temperature, in the range from −30° to 25°C. This article shows the kinetic reasons of this effect. α‐Chymotrypsin was immobilized on celite and used in four different water‐miscible solvents containing small amounts of water‐miscible solvents containing small amounts of water. The reaction studied was the aminolysis of N‐acetyl‐L‐phenylalanine ethyl ester (Ac‐PheOEt) with L‐alaninamide (Ala‐NH2) and water for the acylenzyme complex, the nucleophile was favoured by low reaction temperatures. This effect (quantified as p‐values) was observed in all four solvents, and it was greatest in acetonitrile and tetrahydrofuran. The esterase and amidase activities of the... (More)

A depeptide synthesis was drastically influenced by the reaction temperature, in the range from −30° to 25°C. This article shows the kinetic reasons of this effect. α‐Chymotrypsin was immobilized on celite and used in four different water‐miscible solvents containing small amounts of water‐miscible solvents containing small amounts of water. The reaction studied was the aminolysis of N‐acetyl‐L‐phenylalanine ethyl ester (Ac‐PheOEt) with L‐alaninamide (Ala‐NH2) and water for the acylenzyme complex, the nucleophile was favoured by low reaction temperatures. This effect (quantified as p‐values) was observed in all four solvents, and it was greatest in acetonitrile and tetrahydrofuran. The esterase and amidase activities of the enzyme were studies using AcPheOEt and N‐acetyl‐L‐phenylalanyl‐L‐ananinamide (AcPheAla‐NH2) as substrates. The Michaelis–Menten parameters, Km,app and Vmax, were determined for ester hydrolysis and dipeptide hydrolysis. Both Km,app and Vmax tended to increase with increasing temperature. Secondary hydrolysis was reduced at subzero temperatures because ester hydrolysis was favoured in relation to depeptide hydrolysis. Depeptide synthesis was thus favored by low temperatures in two ways: first, in the competition between the nucleophile and water for the acyl enzyme; and, second, in the competition between the ester substrate and the peptide substrate for the free enzyme. As a result, in acetonitrile containing 10% water, the maximal yield was 99% at −20%C compared with 84% at 25°C. © 1995 John Wiley & Sons, Inc.

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type
Contribution to journal
publication status
published
subject
keywords
cryoenzymology, organic media, peptide synthesis, subzero temperature, α‐chymotrypsin
in
Biotechnology and Bioengineering
volume
46
issue
5
pages
8 pages
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:0029636513
ISSN
0006-3592
DOI
10.1002/bit.260460506
language
English
LU publication?
yes
id
a1011cf6-c062-4de5-847d-4b667182d5f4
date added to LUP
2019-06-22 09:07:09
date last changed
2021-06-20 05:34:07
@article{a1011cf6-c062-4de5-847d-4b667182d5f4,
  abstract     = {{<p>A depeptide synthesis was drastically influenced by the reaction temperature, in the range from −30° to 25°C. This article shows the kinetic reasons of this effect. α‐Chymotrypsin was immobilized on celite and used in four different water‐miscible solvents containing small amounts of water‐miscible solvents containing small amounts of water. The reaction studied was the aminolysis of N‐acetyl‐L‐phenylalanine ethyl ester (Ac‐PheOEt) with L‐alaninamide (Ala‐NH<sub>2</sub>) and water for the acylenzyme complex, the nucleophile was favoured by low reaction temperatures. This effect (quantified as p‐values) was observed in all four solvents, and it was greatest in acetonitrile and tetrahydrofuran. The esterase and amidase activities of the enzyme were studies using AcPheOEt and N‐acetyl‐L‐phenylalanyl‐L‐ananinamide (AcPheAla‐NH<sub>2</sub>) as substrates. The Michaelis–Menten parameters, K<sub>m,app</sub> and V<sub>max</sub>, were determined for ester hydrolysis and dipeptide hydrolysis. Both K<sub>m,app</sub> and V<sub>max</sub> tended to increase with increasing temperature. Secondary hydrolysis was reduced at subzero temperatures because ester hydrolysis was favoured in relation to depeptide hydrolysis. Depeptide synthesis was thus favored by low temperatures in two ways: first, in the competition between the nucleophile and water for the acyl enzyme; and, second, in the competition between the ester substrate and the peptide substrate for the free enzyme. As a result, in acetonitrile containing 10% water, the maximal yield was 99% at −20%C compared with 84% at 25°C. © 1995 John Wiley &amp; Sons, Inc.</p>}},
  author       = {{Jönsson, Åsa and Adlercreutz, Patrick and Mattiasson, Bo}},
  issn         = {{0006-3592}},
  keywords     = {{cryoenzymology; organic media; peptide synthesis; subzero temperature; α‐chymotrypsin}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{5}},
  pages        = {{429--436}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Biotechnology and Bioengineering}},
  title        = {{Effects of subzero temperatures on the kinetics of protease catalyzed dipeptide synthesis in organic media}},
  url          = {{http://dx.doi.org/10.1002/bit.260460506}},
  doi          = {{10.1002/bit.260460506}},
  volume       = {{46}},
  year         = {{1995}},
}