Separation and Purification of Angiotensin Converting Enzyme Inhibitory Peptides Derived from Goat`s Milk Casein Hydrolysates

K J Lee,S B Kim,J W Lim,H S Shin,J S Ryu

doi:10.5713/ajas.2005.741

Abstract

To investigate the basic information and the possibility of ACE-inhibitory peptides for antihypertension materials, goat's caisin (CN) was hydrolyzed by various proteolytic enzymes and ACE-inhibitory peptides were separated and purified. ACE-inhibition ratios of enzymatic hydrolysates of goat's CN and various characteristics of ACE-inhibitory peptides were determined. ACE-inhibition ratios of goat's CN hydrolysates were shown the highest with 87.84% by pepsin for 48 h. By Sephadex G-25 gel chromatograms, Fraction 3 from goat's CN hydrolysates by pepsin for 48 h was confirmed the highest ACE-inhibition activity. Fraction 3 g and Fraction 3 gh from peptic hydrolysates by RP-HPLC to first and second purification were the highest in ACE-inhibition activity, respectively. The most abundant amino acid was leucine (18.83%) in Fraction 3 gh of ACE-inhibitory peptides after second purification. Amino acid sequence analysis of Fraction 3 gh of ACE-inhibitory peptides was shown that the Ala-Tyr-Phe-Tyr, Pro-Tyr-Tyr and Tyr-Leu and Leu-Lys-Asp-Tyr-Gly-Gly-Val-Ser-Leu. IC 5 0 calibrated in peptic hydrolysates at 48 h, Fraction 3, Fraction 3 g and Fraction 3 gh from goat's CN hydrolysates by pepsin for 48 h were 29.89, 3.07, 1.85 and 0.87 g/ml, respectively. Based on the results of this experiment, goat's CN hydrolysates by pepsin were shown to have ACE-inhibitory activity.

Highlights

High blood pressure is a major risk factor in cardiovascular disease
Its inhibitory effect is weaker than that of existing hypertensive agents, its promise is gathering hope in that it commands a large intake since it is provided in a dietary form (Shimizu, 1994). Such dietary Angiotensin converting enzyme (ACE)-inhibitory material is known to exist in the proteolytic hydrolysates of diverse animals, plants and fish (Hara et al, 1987; Kohama, 1988; Miyoshi et al, 1989; Kohmura et al, 1990; Miyoshi et al, 1991; Seki et al, 1993)
The fraction with the highest ACE-inhibitory activity was further analyzed by reverse phase high performance liquid chromatography (RP-HPLC)

Summary

INTRODUCTION

High blood pressure (hypertension) is a major risk factor in cardiovascular disease. Its inhibitory effect is weaker than that of existing hypertensive agents, its promise is gathering hope in that it commands a large intake since it is provided in a dietary form (Shimizu, 1994). Such dietary ACE-inhibitory material is known to exist in the proteolytic hydrolysates of diverse animals, plants and fish (Hara et al, 1987; Kohama, 1988; Miyoshi et al, 1989; Kohmura et al, 1990; Miyoshi et al, 1991; Seki et al, 1993)

MATERIALS AND METHODS

Fraction number

Amino acids