Understanding the Mechanism for the Structure-Activity Relationship of Food-Derived ACEI Peptides

The activity of ACE inhibitory peptides is closely related to their amino acid species, hydrophobic amino acid content, sequence structure, and C-terminal amino acids. In this study, the analysis of databases helps in understanding the relationship mechanism between the structure of an ACEI peptide and its activity. A polypeptide amino acid sequences comparative analysis was done to understand the structural changes including terminal amino acid, amino acid type, molecular weight, and the amino acid location of peptides that affect ACEI activity. Specifically, leucine (L) is the N-terminal peptide responsible for ACE inhibition with the highest frequency of 14.70%. Proline is the C-terminal peptide with the highest frequency of occurrence at 23.21%, while the sum of the frequency of occurrence of the remaining 15 amino acids is less than 40%, indicating that proline has an important role in ACE inhibitory activity. The lower molecular weight peptides showed a higher ACEI as most of the ACEI peptides were smaller than 2kDa. The results of this study may help to understand more fully the relationship and the role of peptide structure in ACE inhibitory activity.