Selection of effective and highly thermostable Bacillus subtilis lipase A template as an industrial biocatalyst-A modern computational approach

Abstract

Biocatalysts are intrinsically reactive and hence their operational stability is of vital significance for any bioprocess. The setback in biocatalyst stability has been tackled from diverse prospects. Inherently, stable biocatalysts are markedly realized and a regular attempt is being made to seek out new organisms that harbor them. Here, we analyzed the industrial biocatalyst lipase A (Native) of Bacillus subtilis and its six thermostable mutants (2M, 3M, 4M, 6M, 9M and 12M) computationally using conformational sampling technique. Consequently, the various structural events deciphering thermostability like root mean square deviation, root mean square fluctuation, radius of gyration and polar surface area showed mutant 12M to be highly stable with statistical validation. Besides, static model analysis involving intra-molecular interactions, secondary structure, solvent accessibility, hydrogen bond pattern, simulated thermal denaturation and desolvation energy also supported 12M comparatively. Of note, the presence of high secondary structural rigidity and hydrogen bonds increased thermostability and functionality of 12M, thus selecting it as a best template for designing thermostable lipases in future. Also, this study has a significant implication toward a better understanding of conformational sampling in enzyme catalysis and enzyme engineering.