In silico and in vitro assessment of yellowfin tuna skin (Thunnus albacares) hydrolysate antioxidation effect

The protein hydrolysate that contains bioactive peptides of yellowfin tuna (Thunnus albacares) skin collagen with antioxidant activity has been successfully studied by using in silico and in vitro assays. We found that using the in silico assessment, the antioxidant peptides can be found from the precursor (type I α1 and α2 collagen of yellowfin tuna). Applying papain as a protease will also provide the greatest degree of hydrolysis for antioxidative peptides. The highest peptide rank peptides sequence such as Pro-Trp-Gly (PWG), Pro-His-Gly (PHG), His-Leu (HL), Ile-Arg (IR), Ala-His (AH), Glu-Leu (EL) that predicted using papain in silico. Molecular docking analysis showed all peptides derived from yellowfin tuna have hindered the substrate to access the active site of myeloperoxidase (MPO). Interestingly, the substitution of the amino acid from His (PHG, 7.1 kcal/mol) to Trp (PWG, 8.0 kcal/mol) has increased the affinity of the peptide towards MPO. They have antioxidative activities used in silico approach to MPO enzyme. We also confirm the in vitro assays for the protein hydrolysate after proteolysis using papain. The concentration and hydrolysis time will give influence the degree of hydrolysis, and antioxidant activities (P