Antibacterial activity of active peptide from marine macroalgae Chondrus crispus protein hydrolysate against Staphylococcus aureus

Macroalgae is a protein source with the potential to yield antimicrobial peptides (AMPs) that exhibit a wide range of biological activities. This study aimed to find bioactive peptide-based antibacterial compounds from marine macroalgae Chondrus crispus protein hydrolysate. The peptides were isolated by solid phase extraction with a strong cation exchanger from trypsin-digested and α-chymotrypsin-digested hydrolysates. Certain fractions of the hydrolyzed protein displayed a good inhibition zone, with the α-chymotrypsin- digested fraction eluted at pH 9 exhibiting the highest inhibition against Gram-negative bacteria Staphylococcus aureus. Several peptides were characterized as cationic helical peptides with hydrophobicity percentages of 16.67–77.78%. The potential antibacterial peptide P01 KKNVTTLAPLVF was identified as an α-helical cationic antibacterial peptide with 0.525 GRAVY value, amphipathic structure, and +2 total charge. Moreover, strong interaction was observed between P07 SAGSGNEGLSGW and P20 RTASSR peptide with DNA gyrase and DHFR receptors from S. aureus with binding energy -8.0 and -7.3 kcal/mol, respectively.