Kaluza G, Kraus A A, Rott R
J Virol. 1975 Jan;17(1):1-9. doi: 10.1128/JVI.17.1.1-9.1976.
A method is described for analysis of viral protein synthesis early after infection when minute amounts of viral proteins are effectively concealed by large amounts of produced host-specific proteins. The method is superior to a radioimmune assay, since all virus-induced proteins can be measured independent of their immunological reactivity. Host-specific protein synthesis can be suppressed by infection with fowl plague virus. Addition of actinomycin C 1.25 h postinfection does not prevent this suppression, but it does block effectively the formation of fowl plague virus-specific proteins. Such cells synthesize only small amounts of cellular proteins, as revealed by polyacrylamide electrophoresis. They can be superinfected with several different enveloped viruses, however, without significant diminution of virus yeilds. In pretreated cells the eclipse is shortened for Semliki Forest virus, Sindbis virus, and vesicular stomatitis virus, but prolonged for Newcastle disease virus. The onset of protein synthesis, specific for the superinfecting virus, could be clearly demonstrated within 1 h after superinfection. At this time, in cells superinfected with Semliki Forest virus, great amounts of NSP 75 (nonstructural protein; molecular weight, 75 X 10(3)) and reduced amounts of the core protein C could be deomonstrated. The precursor glycoprotein NSP 68 is followed by a new polypeptide, NSP 65: three proteins with molecular weights exceeding 100 X 10(3) were observed which are missing later in the infectious cycle. Similar results were obtained after superinfection with Sindbis virus. The formation of a new polypeptide with a molecular weight of about 80 X 10(3) was detected. After superinfection with vesicular stomatis virus or Newcastle disease virus the formation of new proteins, characteristic for the early stage of infeciton, was not observed.
本文描述了一种用于分析感染后早期病毒蛋白合成的方法，此时微量的病毒蛋白会被大量产生的宿主特异性蛋白有效掩盖。该方法优于放射免疫测定法，因为所有病毒诱导的蛋白都能被检测，而不依赖于它们的免疫反应性。用禽瘟病毒感染可抑制宿主特异性蛋白合成。感染后1.25小时添加放线菌素C并不能阻止这种抑制，但它能有效阻断禽瘟病毒特异性蛋白的形成。如聚丙烯酰胺电泳所示，此类细胞仅合成少量细胞蛋白。然而，它们可以被几种不同的包膜病毒超感染，而病毒产量不会显著降低。在预处理的细胞中，塞姆利基森林病毒、辛德毕斯病毒和水疱性口炎病毒的隐蔽期缩短，但新城疫病毒的隐蔽期延长。超感染后1小时内可清楚地证明超感染病毒特异性蛋白合成的开始。此时，在被塞姆利基森林病毒超感染的细胞中，可检测到大量的NSP 75（非结构蛋白；分子量，75×10³）和少量的核心蛋白C。前体糖蛋白NSP 68之后是一种新的多肽NSP 65：观察到三种分子量超过100×10³的蛋白，它们在感染周期后期消失。用辛德毕斯病毒超感染后也得到了类似的结果。检测到一种分子量约为80×10³的新多肽的形成。用水疱性口炎病毒或新城疫病毒超感染后，未观察到感染早期特征性新蛋白的形成。
