玉米大豆复合ACE抑制肽的分离纯化及结构初探

Separation and Structure of Corn/Soybean Compound ACE Inhibitory Peptides

为了探明ACE抑制活性玉米大豆复合肽的结构,采用超滤、Cu^(2+)-Sephadex G-25柱层析、大孔树脂脱盐对复合肽进行分离纯化后,采用HPLC-MS/MS对其中一种复合肽进行了结构鉴定,初步探讨了其构效关系。结果表明:复合粗肽经超滤分离后,得到复合肽的ACE抑制活性大大提高,再经Cu^(2+)-SephadexG-25柱分离后得到两个级分——复合肽Ⅰ和复合肽Ⅱ,前者的ACE抑制活性明显高于后者。复合肽中Pro、Leu、Phe和Ala等氨基酸的含量明显高于原料蛋白质,有助于ACE抑制活性提高。m/z为597.6的质谱峰是一个五肽。结论:m/z为597.6的化合物是氨基酸序列为Leu-Arg-Pro-Asp-Pro的五肽,其端基有助于ACE抑制活性的提高。

In order to find out the structure of angiotensin -Ⅰ- converting enzyme（ACE） inhibitory peptides from the mixture proteins of corn and soybean,ultrafiltration technology,Cu^（2＋）- Sephadex G - 25 column chromatogram, desalting by DA201 - C resin and HPLC - MS/MS were used,and its structure - activity relation was discussed. Results：The ACE activity of the compound peptides is greatly enhanced after the ultrafiltration.Two fractions, i.e.peptidesⅠandⅡ,are gained after Cu^（2＋） - Sephadex G-25 column;the ACE activity of peptidesⅠis markedly higher than that of peptidesⅡ.The contents of Pro,Leu,Phe,Ala in the mixture peptides are higher than those in the material proteins,helping to improve ACE inhibiting ability.m/z 597.6 is a five - peptide.It is concluded that m/z 597.6 is a five - peptide with amino acid sequence of Leu - Arg - Pro - Asp - Pro,and the amino acids at two ends of the chain help to improve ACE inhibitory activity.