Eriquez L A, Knight G B
J Clin Microbiol. 1980 Nov;12(5):667-71. doi: 10.1128/jcm.12.5.667-671.1980.
Cell-associated glutamyl aminopeptidase activity was detected in several strains of Neisseria meningitidis and Moraxella urethralis grown in liquid culture. Enzymatic activity was released from washed cells by ultrasonic treatment and monitored fluorometrically by measuring the release of aryl groups from 17 different aminoacyl-beta-naphthylamides. Substrates containing a glutamyl moiety were readily hydrolyzed by both N. meningitidis and M. urethralis. Glutamyl aminopeptidase activity was partially purified from crude sonicates by means of ion-exchange and gel chromatography, and samples were examined by polyacrylamide gel electrophoresis. Kinetic and pH studies were performed to partially characterize activities. The molecular weight of the M. urethralis enzyme was approximately 88,000, whereas the apparent molecular weight of the N. meningitidis enzyme was shown to be in excess of 200,000. M. urethralis produced two glutamyl aminopeptidases, one specific for a gamma-glutamyl moiety, the other specific for an alpha-glutamyl moiety. In contrast, N. meningitidis produced a single glutamyl aminopeptidase which hydrolyzed alpha- and gamma-glutamyl-substituted beta-naphthylamides.
在液体培养的多株脑膜炎奈瑟菌和尿道莫拉菌中检测到细胞相关的谷氨酰氨肽酶活性。通过超声处理从洗涤过的细胞中释放酶活性，并通过测量17种不同氨基酰-β-萘酰胺中芳基的释放进行荧光监测。含有谷氨酰部分的底物很容易被脑膜炎奈瑟菌和尿道莫拉菌水解。通过离子交换和凝胶色谱从粗超声裂解物中部分纯化谷氨酰氨肽酶活性，并通过聚丙烯酰胺凝胶电泳检查样品。进行动力学和pH研究以部分表征活性。尿道莫拉菌酶的分子量约为88,000，而脑膜炎奈瑟菌酶的表观分子量超过200,000。尿道莫拉菌产生两种谷氨酰氨肽酶，一种对γ-谷氨酰部分具有特异性，另一种对α-谷氨酰部分具有特异性。相比之下，脑膜炎奈瑟菌产生一种单一的谷氨酰氨肽酶，可水解α-和γ-谷氨酰取代的β-萘酰胺。
