Study on Human Cytomegalovirus Proteins - specifically on 65 kDa protein -

65 kDa蛋白被认为是病毒体被膜的组成部分，被膜位于病毒衣壳和外膜之间，经过两年的研究，对65 kDa蛋白的抗原性进行了分析，结果如下：1.使用针对65 kDa蛋白的单特异性和单克隆抗体进行免疫荧光测定以监测该蛋白在感染细胞中的表达。尽管单克隆抗体的反应性存在差异，但所有染色的胞浆包涵体均定位于HCMV诱导的IgG Fc部分受体的位点，表明65 kDa的IgG与HCMV诱导的Fc受体共定位，并具有几种不同的抗原决定簇.发现130、65、50和36 kDa蛋白质的FcR种类介导IgG的结合。通过阻断实验证实了65 kDa蛋白与IgG Fc结合的特异性.本文研究了HCMV诱导的IgG-FcR与65 kDa蛋白上B_2微球蛋白受体的关系。用SV-8蛋白酶消化65 kDa蛋白质产生六种肽。使用针对65 kDa的单克隆和单特异性抗体来绘制消化肽上的抗原决定簇。B_2m也能与分子量为33、32和28的IgG Fc受体结合，说明B_2m与IgG Fc具有相同的结合位点。

The 65 kDa HCMV protein has been considered a constitute of the virion tegument, a poorly defined area located between the capsid and the outer membrane.The study toward analysis of antigenicity of the 65 kDa protein during 2 years has revealed the results as follows.1. Immunofluorescence assay using monospecific and monoclonal antibodies to the 65 kDa protein was carried out to monitor the expression of this protein in infected cells. Regardless of differences in the reactivity of the monoclonal antibodies, all stained cytoplasmic inclusion bodies localized to the site of the HCMV induced receptor for the Fc portion of IgG, suggesting that of the 65 kDa colocalized with HCMV induced FcR and had several different antigenic determinants.2. FcR species of 130, 65, 50 and 36 kDa proteins were found to mediate the binding of IgG. The specificity of binding with of the 65 kDa with IgG Fc were confirmed by the blocking experiments.3. We investigated the relationship between IgG FcR induced by HCMV and B_2 microglobulin receptor on the 65 kDa protein. Digestion of the 65 kDa protein with SV-8 protease generated six peptides. Monoclonal and monospecific antibodies to the 65 kDa were used to map the antigenic determinants on the digested peptides. Peptides with kDa of 33, 32 and 28 on which IgG FcR existed could also be bound by B_2m suggesting that B_2m shares the same binding sites with IgG Fc.