Molecular binding mechanism and identification of novel anti-hypertensive and anti-inflammatory bioactive peptides from camel milk protein hydrolysates

Abstract

Camel milk protein hydrolysates (CMPHs) were investigated for anti-hypertensive and anti-inflammatory activities using in-vitro assays. CMPHs with potent ACE inhibitory and anti-inflammatory activities were subjected to peptide identification and their possible binding mechanism to ACE were depicted via molecular docking. Papain generated CMPHs showed higher degradation of proteins compared to bromelain and alcalase generated CMPHs as depicted in SDS-PAGE profile. Dramatic increase in ACE inhibitory and anti-inflammatory activity was demonstrated in CMPHs with highest activity for papain and alcalase generated hydrolysates, respectively. Based on peptide ranking score, a total of 20, 3 and 43 peptides were potentially regarded as bioactive peptides in hydrolysates A9, B9 and P9, respectively. Binding studies based on pepsite-2 modelling suggested that among 20 potential bioactive peptides in A9 hydrolysate, only 1 (AEWLHDWKL) showed high binding towards three catalytic sites of ACE. While, among 43 bioactive peptides of P9, 14 peptides were found to be potent binder to ACE catalytic sites. Further insight into molecular mechanism of binding revealed that 4 peptides were able to bind to active site of ACE with good docking scores and MM-GBSA binding energies. Overall, the current report remains among very few reports on identification and molecular docking of ACE inhibitory peptides from camel milk.