Simultaneous improvements in the activity and stability of Candida antarctica lipase B through multiple-site mutagenesis

An enzyme with improved characteristics is required for biochemical processes to be economically feasible. In this study, improvements in both the stability and activity of Candida antarctica lipase B (CALB) were integrated through multiple-site mutagenesis. CALB was divided into two regions to optimize its performance. Modulating the flexibility within the substrate-binding region and the hydrophilic solvent-affecting region can enhance the catalytic activity and organic solvent stability of CALB, respectively. Combining the mutation sites from the substrate-binding region and from the hydrophilic solvent-affecting region yielded an enzyme (V139E,A92E) with improved functionality. These findings suggest that the characteristics of CALB can be augmented by modulating its flexibility, and this method can possibly be applied to other lipases.