Bioactive
peptides with blood pressure-lowering functions have received increasing attention. In recent years, many ACE-inhibiting
peptides have been widely purified from various food-derived
proteins and have received considerable interest owing to their potential role in
cardiovascular diseases and in the reduction of side effects. In this study, we hydrolyzed a three-spot seahorse (Hippocampus trimaculatus Leach)
protein by
alcalase to obtain a hydrolysate containing
angiotensin I-converting enzyme (ACE) inhibitory
peptide. Then, the hydrolysate was fractionated by dialysis,
Sephadex G-25 gel filtration chromatography, and reverse-phase high performance liquid chromatography. After consecutive purification, a potent ACE-inhibiting
peptide composed of 8
amino acids (Pro-
Ala-Gly-
Pro-Arg-
Gly-Pro-Ala; MW: 721.39 Da; IC50 value: 7.90 μM) was successfully isolated from three-spot seahorse
protein. For the first time, a novel ACE-inhibiting
peptide (PAGPRGPA) was isolated from the seahorse. Circular dichroism (CD) analyses suggested that the secondary structure of the purified
peptide was mainly composed of random coil. Therefore, the
peptide from seahorse
protein may be used as a favorable ingredient in nutraceuticals, medicines, and functional foods against
antihypertensive and related diseases.