Inhibition of Angiotensin 1-Converting Enzyme by Phosphopeptides in Proteolitic Hydrolysates Derived from Oyster, Crassostrea gigas

• Main Authors: Tamari Masato, Kanda Hiroko
• Format: Report
• Language: English
• Published: 1999
• Subjects: Crassostrea gigas
• Online Access: http://hdl.handle.net/10069/6075; https://nagasaki-u.repo.nii.ac.jp/?action=repository_uri&item_id=23810; https://nagasaki-u.repo.nii.ac.jp/?action=repository_action_common_download&item_id=23810&item_no=1&attribute_id=18&file_no=1

Hydrolysates which inhibit the angiotensin 1-converting enzyme (ACE) were prepared from oyster with three kinds of proteases. The inhibitory activity of ACE detected in the hydrolysates by three kinds of proteases of oyster was fractionated into two major phosphopeptides fractions of P-1 and P-2 in peptic hydrolysates, T-1 and T-2 in tryptic hydrolysates, C-1 and C-2 in chymotryptic hydrolysates by gel filtration chromatography on Sephadex G-50,respectively. The inhibition of ACE of the six kinds of phosphopeptides fractions (P-1,P-2,T-1,T-2,C-1 and C-2) was investigated in vitro. The IC_<50> values of P-1,P-2,T-1,T-2,C-1,and C-2 of phosphopeptides for ACE were 0.3,2.9,2.7,2.6,1.5 and 1.4mg protein/ml, respectively. The pepsin treated fraction P-1 had most inhibition activity and showed 0.3mg protein/ml inhibition against ACE at IC_<50> value. The phosphono-compounds was found in the phosphopeptides fractions of hydrolysates with three kinds of protease. It has been demonstrated that the P-1,P-2,T-1,T-2,C-1 and C-2 contained about 79.13%, 79.19%, 11.07%, 4.71%, 15.26% and 4.49% as phosphonate-phosphorus of total phosphorus. The amino acid compositions of the phosphopeptides fractions (P-1,P-2,T-1,T-2,C-1 and C-2) were characterized by relatively high percentage for glutamic acid, aspartic acid, alanine, lysine and threonine.