Marini M, Urbani A, Trani E, Bongiorno L, Roda L G
Dipartimento di Medicina Sperimentale, Universitá degli Studi di Roma Tor Vergata, Italy.
Peptides. 1997;18(5):741-8. doi: 10.1016/s0196-9781(97)00129-0.
The interindividual variability of the hydrolysis of leucine enkephalin, and of the formation of its hydrolysis by-products has been studied in human plasma. In agreement with known data, the data obtained indicate that Leu-enkephalin is degraded by several enzymes, belonging to three classes: aminopeptidases, dipeptidylaminopeptidases, and dipeptidylcarboxypeptidases. The relative ratio of the substrate degraded by each enzyme class-as well as the expression of the single enzyme species within each class-appears to be individually determined. Interindividual variability observed seems controlled by two main factors: the pattern of enkephalin-degrading enzymes and, more notably, the low molecular weight plasma inhibitors. Both these factors appear to be partially specific of each donor. Possibly because of the composition of these factors, the hydrolysis pattern of the substrate is characteristic of each donor, and constant in blood obtained from successive drawings, at least within a relatively short period of time.
在人体血浆中研究了亮氨酸脑啡肽水解及其水解副产物形成的个体间变异性。与已知数据一致，所获得的数据表明亮氨酸脑啡肽被几种酶降解，这些酶属于三类：氨基肽酶、二肽基氨基肽酶和二肽基羧肽酶。每个酶类降解底物的相对比例以及每个类中单一酶种的表达似乎是个体决定的。观察到的个体间变异性似乎受两个主要因素控制：脑啡肽降解酶的模式，更显著的是低分子量血浆抑制剂。这两个因素似乎对每个供体都有部分特异性。可能由于这些因素的组成，底物的水解模式是每个供体特有的，并且在连续抽取的血液中是恒定的，至少在相对较短的时间内如此。
