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Water plays a different role on activation thermodynamic parameters of alcoholysis reaction catalyzed by lipase in gaseous and organic media.
Graber, Marianne; Bousquet-Dubouch, Marie Pierre; Sousa, Nadine; Lamare, Sylvain; Legoy, Marie Dominique.
Afiliación
  • Graber M; Laboratoire de Génie Protéique et Cellulaire, Bâtiment Marie Curie, Pôle Sciences et Technologies, Université de la Rochelle, Avenue Michel Crépeau, 17042, Cedex 1, La Rochelle, France. mgraber@univ-lr.fr
Biochim Biophys Acta ; 1645(1): 56-62, 2003 Jan 31.
Article en En | MEDLINE | ID: mdl-12535611
The effect of water on the alcoholysis of methyl propionate and n-propanol catalyzed by immobilized Candida antarctica lipase B (CALB) has been compared in a continuous solid-gas reactor and in an organic liquid medium. The enthalpic and entropic contributions of water to the Gibbs free energy of activation in the gas phase were different from the ones in the organic phase, the inverse trends being observed for the variation of both DeltaH* and DeltaS* with water activity. Different phenomena were identified for their influence on the thermodynamic parameters. When increasing a(w), the enhanced flexibility of the enzyme was predominant in the gas phase whereas substrate-solvent interactions due to an increased polarity of the solvent affected mainly the thermodynamic parameters in the organic phase. The observed variations of DeltaG* with water activity were in accordance with kinetics results previously obtained in both reaction media.
Asunto(s)
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Agua / Lipasa Idioma: En Revista: Biochim Biophys Acta Año: 2003 Tipo del documento: Article País de afiliación: Francia
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Agua / Lipasa Idioma: En Revista: Biochim Biophys Acta Año: 2003 Tipo del documento: Article País de afiliación: Francia
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