Leavitt A D, Roberts T M, Garcea R L
J Biol Chem. 1985 Oct 15;260(23):12803-9.
We have expression-cloned in Escherichia coli the major polyoma virus capsid protein, VP1. Under the inducible control of the hybrid tac promoter, VP1 constituted between 2 and 3% of the total host cell protein. The expressed VP1 was purified to near homogeneity with initial yields to 10%. Optimal expression was temperature-dependent, and significant intracellular degradation could be demonstrated. The final product was obtained as one predominant isoelectric focusing species, without the pattern of post-translational modification seen in virus-infected eukaryotic cells. The purified VP1 from E. coli will be useful as a substrate for the purification of VP1 modification enzymes and in the study of inter-VP1 oligomerization.
我们已在大肠杆菌中通过表达克隆出多瘤病毒的主要衣壳蛋白VP1。在杂种tac启动子的诱导控制下，VP1占宿主细胞总蛋白的2%至3%。表达的VP1被纯化至近乎均一，初始产量达10%。最佳表达依赖温度，且可证明有显著的细胞内降解。最终产物是一种主要的等电聚焦条带，没有在病毒感染的真核细胞中所见的翻译后修饰模式。从大肠杆菌中纯化的VP1将作为纯化VP1修饰酶的底物以及用于研究VP1间的寡聚化。
