Yoshimura F, Murakami Y, Nishikawa K, Hasegawa Y, Kawaminami S
Department of Microbiology, School of Dentistry, Aichi-Gakuin University, Nagoya, Aichi, Japan.
J Periodontal Res. 2009 Feb;44(1):1-12. doi: 10.1111/j.1600-0765.2008.01135.x. Epub 2008 Oct 7.
Research on Porphyromonas gingivalis, a periodontopathogen, has provided a tremendous amount of information over the last 20 years, which may exceed in part than that on other closely related members in terms of phylogenetic as well as proteomic criteria, including Bacteroides fragilis and B. thetaiotaomicron as major anaerobic, opportunistic pathogens in the medical field. In this minireview, we focused on recent research findings concerning surface components such as outer membrane proteins and fimbriae, of P. gingivalis.
Elucidation of the surface components in P. gingivalis was especially difficult because outer membrane proteins are tightly bound to lipopolysaccharide and they are resistant to dissociation and separation from each other, even during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, unless samples are appropriately heated. In addition, P. gingivalis is asaccharolytic and therefore a potent proteolytic bacterium, another factor causing difficulty in research. The study of the surface components was carefully carried out considering these unique features in P. gingivalis when compared with other gram-negative bacteria, including Escherichia coli and Pseudomonas aeruginosa.
Separation of outer membrane proteins, and characterization of OmpA-like proteins and RagAB as major proteins, is described herein. Our recent findings on FimA and Mfa1 fimbriae, two unique appendages in this organism, and on their regulation of expression are also described briefly.
Surface components of P. gingivalis somehow have contact with host tissues and cells because of the outermost cell elements. Therefore, such bacterial components are potentially important in the occurrence of periodontal diseases.
在过去20年里，对牙周病原体牙龈卟啉单胞菌的研究提供了大量信息，就系统发育和蛋白质组学标准而言，其信息量可能部分超过了其他密切相关成员，包括脆弱拟杆菌和具核梭杆菌，它们是医学领域主要的厌氧性机会致病菌。在本综述中，我们重点关注了关于牙龈卟啉单胞菌表面成分（如外膜蛋白和菌毛）的最新研究发现。
阐明牙龈卟啉单胞菌的表面成分特别困难，因为外膜蛋白与脂多糖紧密结合，即使在十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳过程中，它们也难以解离和分离，除非对样品进行适当加热。此外，牙龈卟啉单胞菌是无糖分解代谢的，因此是一种强效的蛋白水解细菌，这是研究中的另一个难点。与包括大肠杆菌和铜绿假单胞菌在内的其他革兰氏阴性菌相比，在研究牙龈卟啉单胞菌的表面成分时，充分考虑了其这些独特特征。
本文描述了外膜蛋白的分离以及主要蛋白OmpA样蛋白和RagAB的表征。我们还简要描述了关于该菌中两种独特附属物FimA和Mfa1菌毛及其表达调控的最新发现。
牙龈卟啉单胞菌的表面成分由于是最外层的细胞成分，所以在某种程度上与宿主组织和细胞有接触。因此，这类细菌成分在牙周疾病的发生中可能具有重要意义。
