| Abstract: | Three α-keto ester reductases (yeast keto ester reductase, YKER-II, -IV, -V) were purified from bakers’ yeast. YKER-II, -IV, and -V are dimeric, monomeric, and dimeric enzymes, respectively, and molecular masses are estimated to be 58, 31–39, and 83kDa, respectively, based on gel filtration and SDS- polyacrylamide electrophoresis. Kinetic parameters and stereoselectivities in reduction of α-keto esters have been measured. YKER-IV contributes mainly to reduction by bakers’ yeast at low substrate concentrations, and is useful for synthetic purposes. |
