Xu Y Z, Shawar S M, Dresden M H
Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030.
Exp Parasitol. 1990 Feb;70(2):124-33. doi: 10.1016/0014-4894(90)90093-r.
Membrane-associated leucine aminopeptidase (EC 3.4.11.1, LAP) has been purified to homogeneity from Schistosoma mansoni egg homogenates by a combination of ultracentrifugation, chromatofocusing, and molecular sieve chromatography. A 260-fold increase in specific activity was observed after purification. This is a metalloenzyme, containing carbohydrate moieties. Optimal enzyme activity was found at neutral pH. Enzyme activity was measured using L-leucine-7-amino-4-trifluoromethylcoumarin (L-Leu-AFC); in addition, schistosome egg LAP hydrolyzed a variety of other aminopeptidase substrates. Hydrolysis of L-Leu-AFC was inhibited by a number of aminopeptidase inhibitors, including 1,10-phenanthroline, bestatin, and amastatin.
膜相关亮氨酸氨肽酶（EC 3.4.11.1，LAP）已通过超速离心、色谱聚焦和分子筛色谱相结合的方法从曼氏血吸虫卵匀浆中纯化至同质。纯化后比活性提高了260倍。这是一种金属酶，含有碳水化合物部分。在中性pH值下发现最佳酶活性。使用L-亮氨酸-7-氨基-4-三氟甲基香豆素（L-Leu-AFC）测量酶活性；此外，血吸虫卵LAP还能水解多种其他氨肽酶底物。L-Leu-AFC的水解受到多种氨肽酶抑制剂的抑制，包括1,10-菲咯啉、贝司他汀和抑氨肽酶素。
