Studies on the functions and genetics of pathogenic factors from periodontopathogens.

我们对牙周病原菌牙周杆菌菌毛的致病因子的功能和遗传学进行了研究。2.与Genco博士合作，我们克隆了牙周炎杆菌菌毛主要亚基fimbrin的结构基因。对该基因进行了测序，并以单拷贝形式存在于细菌染色体上，该基因的密码子使用与预期的丰富蛋白非常一致。3、从牙龈假单胞菌的包膜部分中提纯了免疫优势表面抗原--75kodalton的主要蛋白。该蛋白可作为酶联免疫吸附试验的特异性抗原应用于临床研究。4.通过筛选表达的蛋白酶活性克隆牙龈假单胞菌类胰蛋白酶基因的尝试未获成功，提示牙龈假单胞菌的蛋白水解酶基因可能与fimbrlin一样，不能在大肠杆菌和pUC载体系统中表达。

We have carried out the studies on the functions and genetics of pathogenic factors from a periodontopathogen, Bacteroides gingivalis.1, B. gingivalis fimbriae were shown to play an important role on the adherence to buccal epithelial cells.2, In collaboration with Dr. Genco's group, we have cloned the structural gene encoding the fimbrial major subunit, fimbrilin of B. gingivalis. The gene was sequenced and was present as a single copy on the bacterial chromosome, and the codon usage in the gene conformed closely to that expected for an abundant protein.3, The 75-kilodalton major protein, an immunodominant surface antigen was purified to homogeneity from the envelope fraction in B. gingivalis. This protein could be applicable to clinical studies as a specific antigen for an enzyme-linked immunosorbent assay.4, An attempt to clone the gene for a trypsin-like protease in B. gingivalis by screening protease activity expressed remains unsuccessful, suggesting that like fimbrilin, B. gingivalis protease gene may not be expressed in Escherichia coli and pUC plasmids system.