Maturation of fimbria precursor protein by exogenous gingipains in Porphyromonas gingivalis gingipain-null mutant
Maturation of fimbria precursor protein by exogenous gingipains in Porphyromonas gingivalis gingipain-null mutant
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DOI：
10.1111/j.1574-6968.2007.00779.x
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发表时间：
2007-08-01
影响因子：
2.1
通讯作者：
Amano, Atsuo
中科院分区：
文献类型：
--
作者：
Kato, Takahiro;Tsuda, Tetsuhisa;Amano, Atsuo
牙龈卟啉单胞菌表达多种毒力因子，例如菌毛和蛋白酶（称为牙龈蛋白酶），它们是处理前体菌毛蛋白的酶。因此，牙龈蛋白酶缺失突变体缺乏成熟的菌毛。制备含有可溶性牙龈蛋白酶的膜囊泡耗尽上清液（VDS）作为外源性牙龈蛋白酶级分。用 VDS 处理前体蛋白，成功生成了无菌毛的牙龈蛋白酶突变体。实验表明，与流苏型牙龈蛋白酶缺失突变体相比，野生菌株以更高的水平粘附和侵入上皮细胞，而在抑制牙龈蛋白酶活性的胎牛血清的存在下，粘附/侵入被阻止。这项研究的结果表明，牙龈蛋白酶以蛋白水解方式暴露细胞隐性配体，并促进菌毛与上皮细胞结合。
Porphyromonas gingivalis expresses several virulence factors such as fimbriae and proteases, termed gingipains, which are enzymes that process precursor fimbriae proteins. Thus, gingipain-null mutants lack mature fimbriae. Membrane vesicle-depleted supernatants (VDS) containing soluble gingipains were prepared as an exogenous gingipain fraction. Precursor proteins were treated with VDS and a fimbriated gingipain-null mutant was successfully generated. Experiments showed that the wild strain adhered to and invaded epithelial cells at a greater level than the fimbriated gingipain-null mutant, while adhesion/invasion was prevented in the presence of fetal calf serum, which inhibits gingipain activity. The findings of this study suggest that gingipains expose cellular cryptic ligands in a proteolytic manner and promote fimbriae binding to epithelial cells.