Vialard J E, Yuen L, Richardson C D
Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
J Virol. 1990 Dec;64(12):5804-11. doi: 10.1128/JVI.64.12.5804-5811.1990.
A 37-kDa polypeptide specified by Autographa californica nuclear polyhedrosis virus was found to share significant homology with Choristoneura biennis entomopoxyvirus spheroidin protein, which is the major component of entomopoxvirus occlusion bodies. Antibodies raised against spheroidin cross-reacted with the 37-kDa protein and confirmed its expression in the late phase of wild-type baculovirus infection. Immunoblot analysis and fluorescence microscopy demonstrated that the protein was associated with purified A. californica nuclear polyhedrosis virus occlusion bodies and was absent in purified virions. Immunofluorescence studies localized the protein to the periphery of occlusion bodies and the internal membranes of cells infected with wild-type baculovirus. The open reading frame encoding this spheroidinlike protein was inserted into a baculovirus expression vector, and recombinant protein was synthesized under control of the polyhedrin promoter. Studies of the recombinant protein demonstrated that it was heterogeneous in molecular mass as a result of N-linked glycosylation. Tunicamycin inhibited carbohydrate addition and yielded proteins of 34 and 33 kDa.
发现苜蓿银纹夜蛾核型多角体病毒编码的一种37 kDa多肽与双带卷叶蛾昆虫痘病毒的球状体蛋白有显著同源性，球状体蛋白是昆虫痘病毒包涵体的主要成分。针对球状体蛋白产生的抗体与37 kDa蛋白发生交叉反应，并证实其在野生型杆状病毒感染后期表达。免疫印迹分析和荧光显微镜检查表明，该蛋白与纯化的苜蓿银纹夜蛾核型多角体病毒包涵体相关，而在纯化的病毒粒子中不存在。免疫荧光研究将该蛋白定位在包涵体的外周以及感染野生型杆状病毒的细胞内膜上。将编码这种类球状体蛋白的开放阅读框插入杆状病毒表达载体中，并在多角体蛋白启动子的控制下合成重组蛋白。对重组蛋白的研究表明，由于N-连接糖基化，其分子量具有异质性。衣霉素抑制碳水化合物添加，产生34 kDa和33 kDa的蛋白质。
