A comparative analysis of GH18 chitinases and their isoforms from Beauveria bassiana: An in-silico approach

Fifteen different chitinases from various Beauveria bassiana strains were selected and their physicochemical characteristics, secondary structure evaluation and functional analyses were conducted using multiple bioinformatics tools. The molecular mass of chitinases varied from 34.25 to 49.27 kDa, and theoretical pI from 4.81 to 7.94 respectively. Most of the chitinases were hydrophilic, thermostable and negatively charged with good in vivo half-life. Nearly all the chitinases were extracellular with half of them having the standard secretory peptide, and chitinase family 18 active site motif. Phylogeny, multiple sequence alignment and indel analysis confirmed the presence of highly conserved active site residues in seven sequences. Furthermore, a three-dimensional model of chitinase (AIT18869.1) was constructed using the SWISS-MODEL server and validated by ERRAT, Verify 3D and RAMPAGE. The presence of 98.1 % of its residues in the Ramachandran plot’s favoured region further established the quality of the model. CASTp and MetaPocket 2.0 analysis followed by protein-ligand docking using allosamidin and chitotriose thiazoline, suggested Asp-208, Gln-242, Gln-265 and Asn-268 as the most conserved active residues for the enzyme. The information gathered through the in-silico approach would be beneficial in unravelling the properties of B. bassiana chitinases in vitro, which could be subsequently exploited for various industrial applications.