Amano A, Nakamura T, Kimura S, Morisaki I, Nakagawa I, Kawabata S, Hamada S
Division of Special Care Dentistry, Osaka University Faculty of Dentistry, Suita-Osaka, Japan.
Infect Immun. 1999 May;67(5):2399-405. doi: 10.1128/IAI.67.5.2399-2405.1999.
Fimbriae of Porphyromonas gingivalis are thought to play an important role in the colonization and invasion of periodontal tissues. In this study, we analyzed the interactions of P. gingivalis fimbriae with human hemoglobin, fibrinogen, and salivary components (i.e., proline-rich protein [PRP], proline-rich glycoprotein [PRG], and statherin) based on surface plasmon resonance (SPR) spectroscopy with a biomolecular interaction analyzing system (BIAcore). The real-time observation showed that the fimbriae interacted more quickly with hemoglobin and PRG than with other proteins and more intensely with fibrinogen. The significant association constant (ka) values obtained by BIAcore demonstrated that the interactions between fimbriae and these host proteins are specific. These estimated Ka values were not too different; however, the Ka values for hemoglobin (2.43 x 10(6)) and fibrinogen (2.16 x 10(6)) were statistically greater than those for the salivary proteins (1.48 x 10(6) to 1.63 x 10(6)). The Ka value of anti-fimbriae immunoglobulin G for fimbriae was estimated to be 1. 22 x 10(7), which was 6.55-fold higher than the mean Ka value of the host proteins. Peptide PRP-C, a potent inhibitor of PRP-fimbriae interaction, dramatically inhibited fimbrial association to PRP and PRG and was also inhibitory against other host proteins by BIAcore. The binding of fimbriae to these proteins was also evaluated by other methods with hydroxyapatite beads or polystyrene microtiter plates. The estimated binding abilities differed considerably, depending on the assay method that was used. It was noted that the binding capacity of PRP was strongly diminished by immobilization on a polystyrene surface. Taken together, these findings suggest that P. gingivalis fimbriae possess a strong ability to interact with the host proteins which promote bacterial adherence to the oral cavity and that SPR spectroscopy is a useful method for analyzing specific protein-fimbriae interactions.
牙龈卟啉单胞菌的菌毛被认为在牙周组织的定植和侵袭中起重要作用。在本研究中，我们基于表面等离子体共振（SPR）光谱和生物分子相互作用分析系统（BIAcore），分析了牙龈卟啉单胞菌菌毛与人血红蛋白、纤维蛋白原和唾液成分（即富含脯氨酸蛋白[PRP]、富含脯氨酸糖蛋白[PRG]和statherin）之间的相互作用。实时观察表明，菌毛与血红蛋白和PRG的相互作用比与其他蛋白质更快，与纤维蛋白原的相互作用更强烈。BIAcore获得的显著缔合常数（ka）值表明菌毛与这些宿主蛋白之间的相互作用是特异性的。这些估计的Ka值差异不大；然而，血红蛋白（2.43×10⁶）和纤维蛋白原（2.16×10⁶）的Ka值在统计学上高于唾液蛋白（1.48×10⁶至1.63×10⁶）的Ka值。抗菌毛免疫球蛋白G对菌毛的Ka值估计为1.22×10⁷，比宿主蛋白的平均Ka值高6.55倍。肽PRP-C是PRP-菌毛相互作用的有效抑制剂，能显著抑制菌毛与PRP和PRG的结合，并且通过BIAcore对其他宿主蛋白也有抑制作用。菌毛与这些蛋白质的结合也通过使用羟基磷灰石珠或聚苯乙烯微量滴定板的其他方法进行了评估。根据所使用的检测方法，估计的结合能力有很大差异。值得注意的是，PRP固定在聚苯乙烯表面后其结合能力大大降低。综上所述，这些发现表明牙龈卟啉单胞菌菌毛具有与宿主蛋白强烈相互作用的能力，这促进了细菌在口腔中的黏附，并且SPR光谱是分析特异性蛋白-菌毛相互作用的有用方法。
