Molecular docking and in vitro analysis of peptides from Stolephorus indicus with ACE2

Peptides from Stolephorus indicus (Anchovies) meat lysate were generated using a Bacillus subtilis cysteine protease. The peptides were generated by enzyme hydrolysis after which the hydrolysate containing peptides were analysed by LC-MS/MS. Computer aided analysis of peptides using CASTp server and GOLD software show four peptides having ACE2 inhibitory activity. Further, peptides 1 (8 amino acids), 2 (8 amino acid), 5 (9 amino acids) and 11 (12 amino acids) showed good docking features for binding to ACE2 enzyme active sites, mainly by hydrogen bonding. Peptide 1 (8 amino acids-octa-peptide) having the highest docking score was tested in vitro for ACE2 binding and showed up to 40 % inhibition of ACE2 activity at a concentration of 10mM. Hence, this octa-peptide has a potential role in applications involving ACE2 inhibition thereby leading to the prevention of binding of spike glycoprotein to ACE2 receptor.