An In Silico Evaluation of Molecular Interaction Between Antimicrobial Peptide Subtilosin A of Bacillus subtilis with Virulent Proteins of Aeromonas hydrophila

TLDR: The study confirmed that the subtilosin A has more antimicrobial activity to inhibit the Aeromonas toxins by interacting with their binding site residues for preventing extracellular cleavage.

Abstract: Subtilosin A, a cyclic peptide from Bacillus subtilis is known for its antimicrobial activity against a diverse range of bacteria. Herein, we report the specific interaction between subtilosin A against virulent proteins of Aeromonas hydrophila through in silico analysis. Aeromonas toxic proteins such as aerolysin and hemolysin were selected from the non-redundant database. The hemolysin protein was designed by homology modelling tool, and it was validated using Ramachandran plot. Then subtilosin A and target toxin proteins were energy minimized for further docking study. The whole docking experiments were done using antibody mode in Cluspro. Subtilosin A building an active interaction with Aeromonas toxins through H-bonds and protein–protein docking analysis revealed that the hemolysin has 6 H-bond interaction towards the antimicrobial target protein subtilosin A than aerolysin, which has 9 H-bonds. The most favourable interacting residues of subtilosin A are Thr6, Cys13, Ile19, Pro20, Asp21, Phe22, Glu23 and Gly35 involving in the strong H-bond formation and proceeds to inhibition of toxin. Hence, the study confirmed that the subtilosin A has more antimicrobial activity to inhibit the Aeromonas toxins by interacting with their binding site residues for preventing extracellular cleavage.