Mullally M M, Meisel H, FitzGerald R J
Teagasc, National Dairy Products Research Centre, Fermoy, Co. Cork, Ireland.
FEBS Lett. 1997 Feb 3;402(2-3):99-101. doi: 10.1016/s0014-5793(96)01503-7.
The angiotensin-I-converting enzyme (ACE) inhibitory activity of a tryptic digest of bovine beta-lactoglobulin (beta-lg) was investigated. Intact beta-lg essentially did not inhibit ACE while the tryptic digest gave an 84.3% inhibition of ACE. Peptide material eluting between 20 and 25% acetonitrile during C18 solid-phase extraction of the beta-lg tryptic digest inhibited ACE by 93.6%. This solid-phase extraction fraction was shown by mass spectroscopy to contain beta-lg f(142-148). This peptide had an ACE IC50 value of 42.6 micromol/l. The peptide was resistant to further digestion with pepsin and was hydrolysed to a very low extent with chymotrypsin. The contribution of specific amino acid residues within the peptide to ACE inhibitory activity and the potential application of this peptide as a nutraceutical is discussed.
研究了牛β-乳球蛋白（β-lg）胰蛋白酶消化产物的血管紧张素I转换酶（ACE）抑制活性。完整的β-lg基本不抑制ACE，而胰蛋白酶消化产物对ACE的抑制率为84.3%。在β-lg胰蛋白酶消化产物的C18固相萃取过程中，在20%至25%乙腈之间洗脱的肽物质对ACE的抑制率为93.6%。通过质谱分析表明，该固相萃取级分含有β-lg f(142 - 148)。该肽的ACE IC50值为42.6微摩尔/升。该肽对胃蛋白酶的进一步消化具有抗性，对胰凝乳蛋白酶的水解程度非常低。讨论了该肽中特定氨基酸残基对ACE抑制活性的贡献以及该肽作为营养保健品的潜在应用。
