Work

Structural Analysis of New Antihypertensive Peptides Derived from Cheese Whey Protein by Proteinase K Digestion

Year: 1998

Type: article

Abstract: Whey protein was digested with one of seven kinds of proteases at 37°C (trypsin, proteinase K, actinase E, thermolysin, or papain) or at 25°C (pepsin or chymotrypsin) for 24 h.The digested samples were assayed for the inhibitory activity of angiotensinconverting enzyme and for changes in the systolic blood pressure caused in spontaneously hypertensive rats after gastric intubation.The strongest depressive effect on the systolic blood pressure (-55 mm Hg) was observed at 6 h after gastric intubation of the whey protein that was digested by proteinase K. Finally, six peptides were chromatographically isolated from the proteinase K digest by a combination of hydrophobic reversed-phase HPLC and gel filtration.The amino acid sequences and their origins were clarified as follows: Val-Tyr-Pro-Phe-Pro-Gly [b-casein (CN); f 59-64], Gly-Lys-Pro ( b 2 -microglobulin; f 18-20), Ile-Pro-Ala ( b-lactoglobulin; f 78-80), Phe-Pro (serum albumin; f 221-222; b-CN, f 62-63, f 157-158, and f 205-206), Val-Tyr-Pro ( b-CN; f 59-61), and Thr-Pro-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro ( b-CN; f 80-90).Chemical synthesis of these six peptides confirmed that all peptides, except an undecapeptide, have antihypertensive activity in spontaneously hypertensive rats.The synthetic tripeptide Ile-Pro-Ala, originating from b-lactoglobulin, showed the strongest antihypertensive activity (-31 mm Hg). ( Key words: antihypertensive peptide, cheese whey, protease digestion, whey protein) Abbreviation key: ACE = angiotensin-converting enzyme, Hip-His-Leu = hippuryl-histidyl-leucine, IC 50 = 50% inhibitory concentration, RP = reversedphase, SBP = systolic blood pressure, SHR = spontaneously hypertensive rats, TFA = trifluoroacetic acid.

Source: Journal of Dairy Science

DOI: 10.3168/jds.s0022-0302(98)75878-3

Authors: Amhar Abubakar, Tadao Saito, Haruki Kitazawa, Yasushi Kawai, Takatoshi Itoh

Institutions: Universitas Syiah Kuala, Tohoku University

Language: English

Topic: Protein Hydrolysis and Bioactive Peptides

Subfield: Food Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: bronze

Funders: Ministry of Education, Culture, Sports, Science and Technology, Japan Society for the Promotion of Science