Beattie R E, Guthrie D J, Elmore D T, Williams C H, Walker B
Biochem J. 1987 Feb 15;242(1):281-3. doi: 10.1042/bj2420281.
A sensitive assay to determine the activity of leucine aminopeptidase (EC 3.4.11.1), using L-leucine thiobenzyl ester as substrate, was developed. Hydrolysis of the ester by leucine aminopeptidase can be monitored in the presence of 5,5-dithiobis-(2-nitrobenzoic acid) by continuous spectrophotometric measurement at 412 nm. Comparison with some amide substrates showed that the thiol ester provides a much more sensitive assay, its specificity constant (Vmax./Km) being some 3000-fold higher than that of leucine p-nitroanilide.
开发了一种灵敏的测定亮氨酸氨肽酶（EC 3.4.11.1）活性的方法，该方法使用L-亮氨酸硫代苄酯作为底物。在5,5-二硫代双（2-硝基苯甲酸）存在的情况下，通过在412nm处连续分光光度测量，可以监测亮氨酸氨肽酶对酯的水解。与一些酰胺底物的比较表明，硫醇酯提供了一种更为灵敏的测定方法，其特异性常数（Vmax./Km）比亮氨酸对硝基苯胺的特异性常数高约3000倍。
