Isolation and Inhibitory Activity of Angiotensin 1-Converting Enzyme Inhibitor in Enzymatic Hydrolyzate of Hot-Water-Extract from Sea Anemone, Actinia equinia.

Abstract

Author describe a method of extraction and partial purification of phosphoproteins from Sea anemone, actinia equinia. The extraction of the phosphoproteins was carried out with water and hot water. The sea anemone contained two kinds of phosphoproteins (W-P-1, W-P-2) in the water extract and two kinds of phosphoproteins (H-P-1, H-P-2) in the hot water extracts by gel filtration chromatography on Sephadex G-50, respectively. In addition, the ACE inhibitor phosphopeptides of H-P-1 was further purified by ultrafiltration and by Sephadex G-15 chromatography. Inhibitors which inhibit the angiotensin 1-converting enzyme (ACE) were prepared from the pepsin digests of the hot-water-extracts of seaanemone. The inhibitory activity of ACE in the pepsin digests of the hot water extracts (H-P-1) was fractionated into two major phosphopeptides fractions of H-P-1-1 and H-P-1-2 by gel filtration chromatography on Sephadex G-15. The IC_<50> values of H-P-1 and H-P-2 of phosphopeptides for ACE were 23.2 and 15.9 mg protein

ml, respectively. The inhibition of ACE of the two kinds of phosphopeptides fractions (H-P-1-1, H-P-1-2) were analyzed in vitro. The IC_<50> values of H-P-1, H-P-2, H-P-1-1 and H-P-1-2 of phosphopeptides for ACE were 23.26 , 15.91, 0.55 and 0.33 mg protein

ml, respectively. The H-P-1- 2 fraction had most inhibition activity and showed 0.33 mg protein

ml inhibition against ACE at IC_<50> value. The amino acid compositions of the phosphopeptides (H-P-1, H-P-1-1 and H-P-1- 2) were characterized by relatively high percentage for Glu, Asp, Gly, Arg and Lys. It has been demonstrated that the H-P-1, H-P-1-1 and H-P-1-2 contained about 85.8%, 74.2 % and 3.1 % as phosphonate-phosphorus of total phosphorus. The results above, the SephadexG-15 gel filtration patterns of the active fractions obtained from the Sephadex G-50 column chromatography indicated that the molecular weight of the phosphopeptide was about 200～3000.