Premium
Influence of water‐miscible organic solvents on kinetics and enantioselectivity of the ( R ,‐specific alcohol dehydrogenase from Lactobacillus brevis
Author(s) -
Schumacher Jan,
Eckstein Marrit,
Kragl Udo
Publication year - 2006
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.200600039
Subject(s) - acetonitrile , chemistry , lactobacillus brevis , substrate (aquarium) , alcohol dehydrogenase , biocatalysis , solvent , cofactor , mole fraction , enantiomeric excess , enzyme kinetics , kinetics , dehydrogenase , alcohol , organic chemistry , catalysis , enantioselective synthesis , enzyme , reaction mechanism , active site , lactic acid , bacteria , oceanography , physics , quantum mechanics , biology , genetics , geology , lactobacillus plantarum
Abstract Using the organic solvents acetonitrile and 1,4‐dioxane as water‐miscible additives for the alcohol dehydrogenase (ADH)‐catalyzed reduction of butan‐2‐one, we investigated the influence of the solvents on enzyme reaction behavior and enantioselectivity. The NADP + ‐dependent ( R ,‐selective ADH from Lactobacillus brevis (ADH‐LB) was chosen as biocatalyst. For cofactor regeneration, the substrate‐coupled approach using propan‐2‐ol as co‐substrate was applied. Acetonitrile and 1,4‐dioxane were tested from mole fraction 0.015 up to 0.1. Initial rate experiments revealed a complex kinetic behavior with enzyme activation caused by the substrate butan‐2‐one, and increasing K M values with increasing solvent concentration. Furthermore, these experiments showed an enhancement of the enantioselectivity for ( R ,‐butan‐2‐ol from 37% enantiomeric excess (ee) in pure phosphate buffer up to 43% ee in the presence of 0.1 mol fraction acetonitrile. Finally, the influence of the co‐solvents on water activity of the reaction mixture and on enzyme stability was investigated.