Purification of novel angiotensin converting enzyme inhibitory peptides from beef myofibrillar proteins and analysis of their effect in spontaneously hypertensive rat model.

This study was conducted to purify the angiotensin converting enzyme (ACE) inhibitory peptides from beef myofibrillar proteins by using inexpensive enzymes alkaline-AK and papain. Different molecular weight peptides (<3 and <10 kDa) were obtained using ultrafiltration. The <3 kDa peptides obtained by alkaline-AK (AK3K) digestion showed the highest ACE inhibitory activity (74.29%) as compared to other alkaline-AK peptides, and a strong antihypertensive effect of AK3K was observed in the spontaneously hypertensive rat (SHR) model. The AK3K treatment groups (400 and 800 mg/kg body weight) exhibited a decrease in systolic blood pressure (SBP) by 28 and 35 mmHg, respectively in the SHR model. The study demonstrated that the ACE inhibitory peptide obtained from beef myofibrillar proteins had the sequence Leu-Ile-Val-Gly-Ile-Ile-Arg-Cys-Val, and could be possibly used for lowering the SBP.