Tokuda M, Duncan M, Cho M I, Kuramitsu H K
Department of Oral Biology, State University of New York at Buffalo, 14214, USA.
Infect Immun. 1996 Oct;64(10):4067-73. doi: 10.1128/iai.64.10.4067-4073.1996.
Cysteine proteases, including Arg-gingipain of Porphyromonas gingivalis, have been implicated as important virulence factors in periodontal diseases. These enzymes are also involved in the hemagglutinating activity of the organisms. In order to determine the role of proteases in the colonization of the gingival margin, we have compared the attachment properties of P. gingivalis 381 with those of its Arg-gingipain-defective mutant, G-102. Interactions with gram-positive bacteria, human oral epithelial cells, extracellular matrix proteins, and type I collagen were evaluated. In all cases, mutant G-102 was deficient in attachment relative to the parental strain. The mutant's defects could be explained, in part, by the weak autoaggregation displayed by the mutant, which appeared to result from altered fimbrial expression. Both Western blot (immunoblot) and Northern (RNA) blot analyses indicated reduced expression of the major 43-kDa fimbrillin subunit in the mutant. These results suggest that Arg-gingipain may play both direct and indirect roles in the colonization of the gingival margin. In addition, fimbriae may play a direct role in interacting with some host surfaces.
包括牙龈卟啉单胞菌的精氨酸牙龈蛋白酶在内的半胱氨酸蛋白酶，已被认为是牙周疾病中的重要毒力因子。这些酶也参与该生物体的血凝活性。为了确定蛋白酶在牙龈边缘定植中的作用，我们比较了牙龈卟啉单胞菌381与其精氨酸牙龈蛋白酶缺陷型突变体G-102的附着特性。评估了其与革兰氏阳性菌、人口腔上皮细胞、细胞外基质蛋白和I型胶原的相互作用。在所有情况下，相对于亲本菌株，突变体G-102在附着方面存在缺陷。突变体的缺陷部分可以通过突变体表现出的弱自聚集来解释，这似乎是由菌毛表达改变导致的。蛋白质印迹（免疫印迹）和RNA印迹分析均表明，突变体中主要的43 kDa菌毛蛋白亚基表达减少。这些结果表明，精氨酸牙龈蛋白酶可能在牙龈边缘定植中发挥直接和间接作用。此外，菌毛可能在与某些宿主表面相互作用中发挥直接作用。
