Imamura T, Potempa J, Pike R N, Travis J
Department of Biochemistry, University of Georgia, Athens 30602, USA.
Infect Immun. 1995 May;63(5):1999-2003. doi: 10.1128/iai.63.5.1999-2003.1995.
Infection with Porphyromonas gingivalis is strongly associated with adult periodontitis, and proteinases are considered to be important virulent factors of the bacterium. In order to investigate the function of proteinases in disease development we examined vesicles, a biological carrier of these enzymes, for the generation of vascular permeability enhancement (VPE) activity, believed to correlate with the exudation of gingival crevicular fluid. The vesicles generated VPE activity from human plasma in a dose-dependent manner which could be inhibited 90% by antipain, a specific inhibitor of the Arg-specific cysteine proteinases (Arg-gingipains [RGPs] from P. gingivalis. Incubation of vesicles with high-molecular-weight-kininogen (HMWK)-deficient plasma did not result in VPE activity. On this basis, RGPs associated with vesicles were assumed to be responsible for most of the VPE activity generation via plasma prekallikrein activation and subsequent bradykinin production. The secondary pathway for VPE activity production was dependent on the direct release of bradykinin from HMWK by the concerted action of RGP and a Lys-specific cysteine proteinase (Lys-gingipain [KGP]), also associated with vesicles. These results indicate that RGP and KGP are biologically important VPE factors acting either via prekallikrein activation (RGP) and/or HMWK cleavage (RGP and KGP) to release BK and, thereby, contributing to the production of gingival crevicular fluid at periodontal sites infected with P. gingivalis.
牙龈卟啉单胞菌感染与成人牙周炎密切相关，蛋白酶被认为是该细菌的重要致病因素。为了研究蛋白酶在疾病发展中的作用，我们检测了作为这些酶生物载体的囊泡，以观察其是否具有血管通透性增强（VPE）活性，这种活性被认为与龈沟液渗出相关。囊泡以剂量依赖的方式从人血浆中产生VPE活性，该活性可被抗蛋白酶抑制90%，抗蛋白酶是牙龈卟啉单胞菌精氨酸特异性半胱氨酸蛋白酶（精氨酸牙龈蛋白酶[RGPs]）的特异性抑制剂。用高分子量激肽原（HMWK）缺陷型血浆孵育囊泡不会产生VPE活性。基于此，推测与囊泡相关的RGPs通过激活血浆前激肽释放酶并随后产生缓激肽，从而对大部分VPE活性的产生负责。VPE活性产生的次要途径依赖于缓激肽从HMWK的直接释放，这是由同样与囊泡相关的RGP和赖氨酸特异性半胱氨酸蛋白酶（赖氨酸牙龈蛋白酶[KGP]）共同作用实现的。这些结果表明，RGP和KGP是生物学上重要的VPE因子，它们通过激活前激肽释放酶（RGP）和/或切割HMWK（RGP和KGP）来释放BK，从而促进感染牙龈卟啉单胞菌的牙周部位龈沟液的产生。
