Shifting pH optimum of Bacillus circulans xylanase based on molecular modeling.

摘要

Industrial use of enzymes can be limited by the necessity to use a non-optimal pH. This study used a protein engineering technique in an attempt to adjust the pH optima of 4 hydrolases and their mutants. Changes in electrostatic potential were calculated using Delphi, and were compared to measured changes in pH optima. Results indicated that changes in electrostatic potential can be used as an indicator for selecting promising mutants. Of the Bacillus circulans xylanase mutants assessed by molecular modelling, Gln167Met and Arg73Val had a higher pH optimum than the wild type, while Lys175Gln showed a similar pH-activity profile to the wild-type enzyme.