Enhancement of hydrogen peroxide tolerance of lipase LipA from Bacillus subtilis using semi-rational design

摘要

In many application fields, microbial lipases have to coexist with hydrogen peroxide in the same reaction system and it is necessary to construct hydrogen peroxide-tolerant lipase mutant variants. Mass changes between native amino acids and the oxidized amino acids by hydrogen peroxide were determined using mass spectrometry in early research. Based on the known 3D structure information and mass spectrometric analysis data, an extremely small library of Bacillus subtilis lipase LipA consisting of twenty-six mutant variants was constructed and screened. From the mutation library, total twenty-one lipase LipA mutant variants improved hydrogen peroxide tolerance. Compared with that of lipase LipA, the C-50 value and t(1/2) value of the best mutant variant, LipA-Trp(42)Ala/Met(134)Glu was increased by 9.1-fold and 9.5-fold, respectively.