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Enzyme catalysis in uni- and bi-continuous microemulsions : Dependence of kinetics on substrate partitioning

Larsson, Karin M. ; Adlercreutz, Patrick LU orcid ; Mattiasson, Bo LU and Olsson, Ulf LU (1991) In Journal of the Chemical Society, Faraday Transactions 87(3). p.465-471
Abstract

The kinetics of enzymatic conversion in a microemulsion have been investigated. Racemic 3-methylcyclohexanone was oxidized by horse-liver alcohol dehydrogenase (HLADH, E.C. 1.1.1.1.) using a coupled substrate-coenzyme regenerating cycle in a sodium bis-(2-ethylhexyl) sulphosuccinate (AOT)-isooctane-buffer microemulsion. Initial enzyme activity was measured as a function of the oil volume fraction in the range 0 ≤ Φ ≤ 0.83 for a constant surfactant concentration. The change in composition is followed by a change in microstructure from oil-in-water (O/W) to water-in-oil (W/O) via a bicontinuous structure as determined by self-diffusion measurements using the pulsed-gradient NMR technique. The variation of the initial rate with composition... (More)

The kinetics of enzymatic conversion in a microemulsion have been investigated. Racemic 3-methylcyclohexanone was oxidized by horse-liver alcohol dehydrogenase (HLADH, E.C. 1.1.1.1.) using a coupled substrate-coenzyme regenerating cycle in a sodium bis-(2-ethylhexyl) sulphosuccinate (AOT)-isooctane-buffer microemulsion. Initial enzyme activity was measured as a function of the oil volume fraction in the range 0 ≤ Φ ≤ 0.83 for a constant surfactant concentration. The change in composition is followed by a change in microstructure from oil-in-water (O/W) to water-in-oil (W/O) via a bicontinuous structure as determined by self-diffusion measurements using the pulsed-gradient NMR technique. The variation of the initial rate with composition is well described by modifying the rate equation, valid in pure buffer, by simply taking into account the partitioning of the substrates between the polar and apolar microdomains in the structured solvent. Also the enzyme stability was investigated at various compositions of the microemulsion. The stability was found to increase with increasing Φ.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the Chemical Society, Faraday Transactions
volume
87
issue
3
pages
7 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:0003444335
ISSN
0956-5000
DOI
10.1039/FT9918700465
language
English
LU publication?
yes
id
7acdd98c-796d-49e3-bbae-5925cee7af47
date added to LUP
2019-06-22 18:47:28
date last changed
2022-04-11 14:48:01
@article{7acdd98c-796d-49e3-bbae-5925cee7af47,
  abstract     = {{<p>The kinetics of enzymatic conversion in a microemulsion have been investigated. Racemic 3-methylcyclohexanone was oxidized by horse-liver alcohol dehydrogenase (HLADH, E.C. 1.1.1.1.) using a coupled substrate-coenzyme regenerating cycle in a sodium bis-(2-ethylhexyl) sulphosuccinate (AOT)-isooctane-buffer microemulsion. Initial enzyme activity was measured as a function of the oil volume fraction in the range 0 ≤ Φ ≤ 0.83 for a constant surfactant concentration. The change in composition is followed by a change in microstructure from oil-in-water (O/W) to water-in-oil (W/O) via a bicontinuous structure as determined by self-diffusion measurements using the pulsed-gradient NMR technique. The variation of the initial rate with composition is well described by modifying the rate equation, valid in pure buffer, by simply taking into account the partitioning of the substrates between the polar and apolar microdomains in the structured solvent. Also the enzyme stability was investigated at various compositions of the microemulsion. The stability was found to increase with increasing Φ.</p>}},
  author       = {{Larsson, Karin M. and Adlercreutz, Patrick and Mattiasson, Bo and Olsson, Ulf}},
  issn         = {{0956-5000}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{3}},
  pages        = {{465--471}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Journal of the Chemical Society, Faraday Transactions}},
  title        = {{Enzyme catalysis in uni- and bi-continuous microemulsions : Dependence of kinetics on substrate partitioning}},
  url          = {{http://dx.doi.org/10.1039/FT9918700465}},
  doi          = {{10.1039/FT9918700465}},
  volume       = {{87}},
  year         = {{1991}},
}