Identification of ACE inhibitory peptides from red algaMazzaella japonica

Angiotensin I converting enzyme (ACE) inhibition is one of the key factors for cardiovascular disease, and inhibition of ACE activity is related to the prevention of high blood pressure. Until now, some ACE inhibitory peptides have been found in the protein hydrolysates of red algae, and most of them were derived from phycobiliproteins and rubisco. In this study, we modified the preparation method to evaluate the potential of ACE inhibitory activity from protein hydrolysate of red algaMazzaella japonicaexcept for phycobiliproteins and rubisco. As a result, we identified 11 peptides (YRD, VSEGLD, TIMPHPR, GGPAT, SSNDYPI, SRIYNVKSNG, VDAHY, CPYDWV, YGDPDHY, NLGN and DFGVPGHEP) in the hydrolysate by the reversed phase-HPLC and MALDI-TOF/MS/MS. Among them, YRD would be derived from phycoerythrin alpha-subunit. However, the others would be from other proteins encoded in chloroplast or nuclear genomes. This study revealed that not only phycobiliproteins and rubisco but also the other proteins in red algae have the potential for the source of ACE inhibitory peptide.