Substrate specificity of the γ-isoenzyme of recombinant pig liver esterase towards acetates of secondary alcohols

The γ-isoenzyme of pig liver esterase (rPLE) was produced recombinantly by expression in Pichia pastoris. A comparison of rPLE with commercial preparations of crude PLE revealed significant differences in the kinetic resolution of a series of acetates of secondary alcohols. With rPLE substantially higher enantioselectivities were observed in the hydrolysis of (R,S)-1-phenyl-3-butyl acetate, (R,S)-1-phenyl-2-propyl acetate, (R,S)-1-phenyl-2-pentyl acetate, and (R,S)-1-phenyl-2-butyl acetate. For the first two compounds, also an inversed stereopreference was found. This change in substrate specificity can be related to varying contents of the γ-isoenzyme in commercial PLE preparations and the presence of further isoenzymes with different properties.