Grenier D, Gauthier P, Plamondon P, Nakayama K, Mayrand D
Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire and Faculté des Sciences et de Génie, Université Laval, Québec, Canada.
Oral Microbiol Immunol. 2001 Aug;16(4):212-7. doi: 10.1034/j.1399-302x.2001.160403.x.
Porphyromonas gingivalis is an asaccharolytic bacterium that requires nitrogen substrates as carbon and energy sources. The aims of this study were to investigate the aminopeptidase activities of P. gingivalis and to evaluate the effect of aminopeptidase inhibitors on bacterial growth. Only arginine aminopeptidase and dipeptidyl aminopeptidase IV activities were detected. Experimental evidence was obtained suggesting that the Arg-gingipains of P. gingivalis can function as both an endopeptidase and an aminopeptidase. Firstly, the arginine aminopeptidase activity was found to be inhibited by leupeptin, a well-known inhibitor of Arg-gingipain activity. Secondly, a preparation of Arg-gingipain activity could hydrolyze the chromogenic substrate for arginine aminopeptidase. Lastly, a mutant of P. gingivalis constructed via gene disruption by use of suicide plasmids and deficient in both Arg-gingipain A and B was also devoid of arginine aminopeptidase activity. To investigate the key role of aminopeptidase activities in growth of P. gingivalis, aminopeptidase inhibitors were incorporated in the culture medium prior to inoculation. Bestatin and actinonin were the only ones to inhibit growth of P. gingivalis. Their mechanism of growth inhibition appears to be different but does not involve inhibition of the two major aminopeptidase activities (arginine aminopeptidase and dipeptidyl aminopeptidase IV).
牙龈卟啉单胞菌是一种无糖分解代谢的细菌，它需要氮底物作为碳源和能源。本研究的目的是调查牙龈卟啉单胞菌的氨肽酶活性，并评估氨肽酶抑制剂对细菌生长的影响。仅检测到精氨酸氨肽酶和二肽基氨肽酶IV的活性。获得的实验证据表明，牙龈卟啉单胞菌的精氨酸牙龈蛋白酶可同时作为一种内肽酶和氨肽酶发挥作用。首先，发现亮抑蛋白酶肽（一种众所周知的精氨酸牙龈蛋白酶活性抑制剂）可抑制精氨酸氨肽酶活性。其次，精氨酸牙龈蛋白酶活性制剂可水解精氨酸氨肽酶的生色底物。最后，通过使用自杀质粒进行基因破坏构建的、缺乏精氨酸牙龈蛋白酶A和B的牙龈卟啉单胞菌突变体也没有精氨酸氨肽酶活性。为了研究氨肽酶活性在牙龈卟啉单胞菌生长中的关键作用，在接种前将氨肽酶抑制剂加入培养基中。贝他汀和放线菌素是仅有的能抑制牙龈卟啉单胞菌生长的物质。它们的生长抑制机制似乎不同，但不涉及对两种主要氨肽酶活性（精氨酸氨肽酶和二肽基氨肽酶IV）的抑制。
