改进的分光光度计法测定食源性多肽血管紧张素转化酶的抑制活性

Modified spectrophotometric method for assay of angiotensin Ⅰ-converting enzyme inhibitory activity of food-derived peptides

在传统检测食源性多肽血管紧张素转化酶(ACE)抑制肽体外活性方法的基础上,结合纸层析测定马尿酸的方法对其进行改进,建立了一种新的分光光度法用于测定样品中ACE的抑制活性.结果表明:该方法确定的显色反应吸收波长为459 nm;最佳显色温度为40℃;最佳显色时间为30 min;最佳显色剂质量分数为0.5%;用卡托普利和有ACE抑制活性的棉籽蛋白肽作为样品进行检测验证,结果表明,此方法简便、灵敏、准确、重复性好,可用于筛选食源性ACE抑制肽.

A modified spectrophotometric assay was developed for determination of angiotensin Iconverting enzyme （ACE） inhibitory activity of peptides derived from plant protein, which was based on the classical paper chromatography determination of hippurie acid （HA） content in the urine. By using the modified method, the maximum absorbance of HA was measured at 459 nm, and the optimum chromogenic reaction conditions were as follows： temperature of 40℃, time for 30 min, and the DAB concentration of 0.5 %. Captopril and cottonseed protein peptides showing antihypertensive activity as inhibitors of ACE were detected by this modified spectrophotometric assay. The result showed that the modified method was proved to be convenient, sensitive, accurate and reproducible, and it could be used for the screening of ACE inhibitory peptides derived from food proteins.