Freund R, Garcea R L, Sahli R, Benjamin T L
Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115.
J Virol. 1991 Jan;65(1):350-5. doi: 10.1128/JVI.65.1.350-355.1991.
The plaque size and hemagglutination characteristics of five cloned wild-type strains of polyomavirus were determined. The strains fell into two groups, those with large or small plaques, each with distinctive hemagglutination behavior at different temperatures and pHs. The nucleotide sequence of VP1, the major capsid protein of the virus, was determined for each of the viral strains. The PTA (large-plaque) and RA (small-plaque) strains differed only at residue 92 of VP1, where there is a glutamic acid or glycine, respectively (R. Freund, A. Calderone, C. J. Dawe, and T. L. Benjamin, J. Virol. 65:335-341, 1991). The same amino acid difference in VP1 correlated with plaque size and hemagglutination properties of the other sequenced viruses. Mutagenesis converting amino acid 92 from glutamic acid to glycine converted the plaque size and hemagglutination behavior of the large-plaque PTA strain to that of a small-plaque strain. Furthermore, PTA and RA VP1 proteins produced in Escherichia coli behaved as their parental viruses did in hemagglutination assays. These results demonstrate that amino acid residue 92 of VP1 is involved in determining the plaque size and hemagglutination behavior of polyomavirus and strongly suggest that this region of the VP1 polypeptide interacts directly with cell receptors.
测定了五种克隆的野生型多瘤病毒株的噬斑大小和血凝特性。这些毒株分为两组，即具有大噬斑或小噬斑的毒株，每组在不同温度和pH值下具有独特的血凝行为。测定了每种病毒株病毒主要衣壳蛋白VP1的核苷酸序列。PTA（大噬斑）株和RA（小噬斑）株仅在VP1的第92位残基处不同，分别为谷氨酸或甘氨酸（R. Freund、A. Calderone、C. J. Dawe和T. L. Benjamin，《病毒学杂志》65:335 - 341，1991年）。VP1中相同的氨基酸差异与其他测序病毒的噬斑大小和血凝特性相关。将第92位氨基酸从谷氨酸突变为甘氨酸，可使大噬斑PTA株的噬斑大小和血凝行为转变为小噬斑株的。此外，在大肠杆菌中产生的PTA和RA VP1蛋白在血凝试验中的表现与其亲本病毒相同。这些结果表明，VP1的第92位氨基酸残基参与决定多瘤病毒的噬斑大小和血凝行为，并强烈提示VP1多肽的这一区域直接与细胞受体相互作用。
