Murphy T F, Bartos L C
Department of Medicine, State University of New York at Buffalo 14215.
Infect Immun. 1988 May;56(5):1084-9. doi: 10.1128/iai.56.5.1084-1089.1988.
The protein P2 comprises a large proportion of the outer membrane of nontypable Haemophilus influenzae and functions as a porin. In view of the importance of the protein as a surface antigen, the present study was designed to purify and analyze P2 with particular emphasis on detection of antigenic determinants expressed on the bacterial surface and identification of bactericidal targets on P2. The P2 protein was purified by using detergent solubility, anion-exchange chromatography, and gel-filtration chromatography sequentially. Two monoclonal antibodies to P2 were developed. One antibody (2E6) recognized a determinant expressed on the bacterial surface, whereas the other antibody (3F3) recognized an internal epitope. The surface-exposed 2E6 determinant was present on 12% of strains from a nationwide collection. P2 is a bactericidal target for antibody 2E6. Cyanogen bromide cleavage of P2 resulted in two fragments, as in type b strains. Both monoclonal antibodies recognized epitopes on the larger fragment. These observations have potentially important implications regarding the development of vaccines to prevent H. influenzae infections and the development of a serotyping system for epidemiologic studies.
蛋白质P2占不可分型流感嗜血杆菌外膜的很大一部分，起孔蛋白的作用。鉴于该蛋白质作为表面抗原的重要性，本研究旨在纯化和分析P2，特别着重于检测细菌表面表达的抗原决定簇以及鉴定P2上的杀菌靶点。通过依次使用去污剂溶解性、阴离子交换色谱法和凝胶过滤色谱法纯化P2蛋白。制备了两种针对P2的单克隆抗体。一种抗体（2E6）识别细菌表面表达的一个决定簇，而另一种抗体（3F3）识别一个内部表位。来自全国范围内收集的菌株中，有12%存在表面暴露的2E6决定簇。P2是抗体2E6的杀菌靶点。与b型菌株一样，P2经溴化氰裂解产生两个片段。两种单克隆抗体都识别较大片段上的表位。这些观察结果对于预防流感嗜血杆菌感染的疫苗开发以及用于流行病学研究的血清分型系统的开发可能具有重要意义。
