Lafferty M A, Raducha M, Harris H
Curr Eye Res. 1984 Aug;3(8):1017-31. doi: 10.3109/02713688409011748.
Soluble exopeptidases present in bovine and human lenses were identified and characterized using starch gel electrophoresis separation followed by activity staining with an L-aminoacid oxidase/peroxidase system or a naphthylamine fluorescence system. Sixteen peptide and twelve naphthylamide substrates were used. The profile of substrate specificities for each electrophoretically separated exopeptidase was determined. Characterization also included the effects on activity of pH, EDTA, puromycin, and divalent cations. In addition, molecular weight determinations by gel filtration were made. Six bovine lens peptidases were identified including leucine aminopeptidase and dipeptidylpeptidase III and six human lens peptidase including dipeptidylpeptidase III. Strong homology in terms of substrate specificity and molecular weight was seen between bovine leucine aminopeptidase and one of the human peptidases previously designated peptidase "S". The findings indicate the diversity of exopeptidase available for polypeptide degradation in lens.
利用淀粉凝胶电泳分离，随后用L-氨基酸氧化酶/过氧化物酶系统或萘胺荧光系统进行活性染色，对牛和人晶状体中的可溶性外肽酶进行了鉴定和表征。使用了16种肽和12种萘酰胺底物。确定了每种经电泳分离的外肽酶的底物特异性概况。表征还包括pH、EDTA、嘌呤霉素和二价阳离子对活性的影响。此外，通过凝胶过滤测定了分子量。鉴定出六种牛晶状体肽酶，包括亮氨酸氨肽酶和二肽基肽酶III，以及六种人晶状体肽酶，包括二肽基肽酶III。在底物特异性和分子量方面，牛亮氨酸氨肽酶与先前命名为肽酶“S”的一种人肽酶之间存在很强的同源性。研究结果表明晶状体中可用于多肽降解的外肽酶具有多样性。
