Effect of water activity on the rate profile of subtilisin Carlsberg in toluene in the presence of an organo-soluble acid- base buffer

N. Harper, M. Dolman, B.D. Moore, P.J. Halling

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The ionisation state of the enzyme and the water activity (alpha (w)) of the system are two important factors which affect catalytic activity in low-water organic solvents. Here we investigate the interaction between effects of alpha (w) and the ionisation state of subtilisin Carlsberg, controlled by an organo-soluble dendrimer buffer. It was shown that alpha (w) does not have a major effect on the relationship between rate of transesterification in toluene and buffer ratio, [sodium salt]/[acid]. The weak dependence on alpha (w) (between 0.54 and 0.85) probably reflects compensating effects on ionisation equilibria for the buffer and the carboxyl groups on the enzyme. (C) 2001 Elsevier Science Inc. All rights reserved.
LanguageEnglish
Pages413-416
Number of pages3
JournalEnzyme and Microbial Technology
Volume29
Issue number6-7
DOIs
Publication statusPublished - 4 Oct 2001

Fingerprint

Subtilisins
Toluene
Ionization
Buffers
Acids
Water
Dendrimers
Transesterification
Enzymes
Organic solvents
Catalyst activity
Salts
Sodium

Keywords

  • subtilisin
  • organic solvents
  • ionisation state
  • water activity
  • buffer
  • Dendritic macromolecules
  • convergent approach
  • solvents
  • enzymes
  • state
  • media
  • ph
  • biocatalysis

Cite this

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title = "Effect of water activity on the rate profile of subtilisin Carlsberg in toluene in the presence of an organo-soluble acid- base buffer",
abstract = "The ionisation state of the enzyme and the water activity (alpha (w)) of the system are two important factors which affect catalytic activity in low-water organic solvents. Here we investigate the interaction between effects of alpha (w) and the ionisation state of subtilisin Carlsberg, controlled by an organo-soluble dendrimer buffer. It was shown that alpha (w) does not have a major effect on the relationship between rate of transesterification in toluene and buffer ratio, [sodium salt]/[acid]. The weak dependence on alpha (w) (between 0.54 and 0.85) probably reflects compensating effects on ionisation equilibria for the buffer and the carboxyl groups on the enzyme. (C) 2001 Elsevier Science Inc. All rights reserved.",
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author = "N. Harper and M. Dolman and B.D. Moore and P.J. Halling",
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T1 - Effect of water activity on the rate profile of subtilisin Carlsberg in toluene in the presence of an organo-soluble acid- base buffer

AU - Harper, N.

AU - Dolman, M.

AU - Moore, B.D.

AU - Halling, P.J.

PY - 2001/10/4

Y1 - 2001/10/4

N2 - The ionisation state of the enzyme and the water activity (alpha (w)) of the system are two important factors which affect catalytic activity in low-water organic solvents. Here we investigate the interaction between effects of alpha (w) and the ionisation state of subtilisin Carlsberg, controlled by an organo-soluble dendrimer buffer. It was shown that alpha (w) does not have a major effect on the relationship between rate of transesterification in toluene and buffer ratio, [sodium salt]/[acid]. The weak dependence on alpha (w) (between 0.54 and 0.85) probably reflects compensating effects on ionisation equilibria for the buffer and the carboxyl groups on the enzyme. (C) 2001 Elsevier Science Inc. All rights reserved.

AB - The ionisation state of the enzyme and the water activity (alpha (w)) of the system are two important factors which affect catalytic activity in low-water organic solvents. Here we investigate the interaction between effects of alpha (w) and the ionisation state of subtilisin Carlsberg, controlled by an organo-soluble dendrimer buffer. It was shown that alpha (w) does not have a major effect on the relationship between rate of transesterification in toluene and buffer ratio, [sodium salt]/[acid]. The weak dependence on alpha (w) (between 0.54 and 0.85) probably reflects compensating effects on ionisation equilibria for the buffer and the carboxyl groups on the enzyme. (C) 2001 Elsevier Science Inc. All rights reserved.

KW - subtilisin

KW - organic solvents

KW - ionisation state

KW - water activity

KW - buffer

KW - Dendritic macromolecules

KW - convergent approach

KW - solvents

KW - enzymes

KW - state

KW - media

KW - ph

KW - biocatalysis

UR - http://dx.doi.org/10.1016/S0141-0229(01)00403-3

U2 - 10.1016/S0141-0229(01)00403-3

DO - 10.1016/S0141-0229(01)00403-3

M3 - Article

VL - 29

SP - 413

EP - 416

JO - Enzyme and Microbial Technology

T2 - Enzyme and Microbial Technology

JF - Enzyme and Microbial Technology

SN - 0141-0229

IS - 6-7

ER -