Mintz K P, Fives-Taylor P M
Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, College of Medicine, University of Vermont, Burlington 05405.
Infect Immun. 1994 Oct;62(10):4500-5. doi: 10.1128/iai.62.10.4500-4505.1994.
Actinobacillus actinomycetemcomitans expresses proteins that bind to the Fc portion of immunoglobulins. The immunoglobulin Fc receptors on the surface of A. actinomycetemcomitans were detected by the binding of biotinylated human or murine Fc molecules to strain SUNY 465 adsorbed to the bottom of microtiter wells. Biotinylated Fc binding was inhibited by unlabeled Fc molecules and human plasma. Fc receptors were identified by the binding of biotinylated Fc molecules to bacterial membrane proteins separated by polyacrylamide gel electrophoresis and transferred to nitrocellulose. Multiple bands were identified, and the major Fc-binding protein was determined to be a heat-modifiable protein. This protein migrated with approximate molecular weights of 25,000 and 32,000 (unheated and heated, respectively). Amino-terminal sequence analysis of this protein revealed a sequence identical to the heat-modifiable protein described for A. actinomycetemcomitans ATCC 43718. This protein sequence exhibits significant homology with the N termini of outer membrane protein A (OmpA) of Escherichia coli and related OmpA-like proteins from other gram-negative bacteria.
伴放线放线杆菌表达与免疫球蛋白Fc部分结合的蛋白质。通过生物素化的人或鼠Fc分子与吸附在微量滴定板孔底部的菌株SUNY 465结合，检测伴放线放线杆菌表面的免疫球蛋白Fc受体。未标记的Fc分子和人血浆可抑制生物素化Fc的结合。通过生物素化Fc分子与经聚丙烯酰胺凝胶电泳分离并转移至硝酸纤维素膜上的细菌膜蛋白结合来鉴定Fc受体。鉴定出多条带，主要的Fc结合蛋白被确定为一种热可修饰蛋白。该蛋白迁移时的近似分子量分别为25,000和32,000（分别为未加热和加热状态）。对该蛋白进行氨基末端序列分析，发现其序列与伴放线放线杆菌ATCC 43718中描述的热可修饰蛋白相同。该蛋白序列与大肠杆菌外膜蛋白A（OmpA）的N末端以及来自其他革兰氏阴性菌的相关OmpA样蛋白的N末端具有显著同源性。
