Molecular and Immunological Analysis of the Human Polyomavirus,JC Virus,Major Capsid Protein VP1

• Main Authors: Ling-Hua Chen, 陳玲華
• Other Authors: Deching Chang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/67985270177551743411

碩士 === 中山醫學院 === 免疫學研究所 === 89 === Abstract Human JC virus (JCV) belongs to the family of polyomaviridae. The viral capsid is composed of 72 capsomeres. Five VP1 molecules make up a capsomere structure. To investigate the minimal sequences on JCV VP1 polypeptide required for capsid assembly, the first twelve (△N12) and nineteen (△N19) amino acids at the N-terminus and the last sixteen (△C16), seventeen (△C17) and thirty-one (△C31) amino acids at the C-terminus of VP1 were truncated and expressed in E. coli. The VP1 proteins of △N12 and △C16 were able to self-assemble into a virus-like particle similar to that of wild type (WT) VP1. However, the mutant proteins of △N19, △C17 and △C31 formed a pentameric capsomere structure as demonstrated by a 10-30% sucrose gradient centrifugation and 5-20% sucrose gradient centrifugation and electron microscopy. These results suggest that the first nineteen and the last seventeen residues are the minimal sequences on VP1 polypeptide for JCV capsid assembly. Although DNA sequences of JCV,SV40 and Py are highly homologous,their host ranges are different. The results of immunological analysis showed that the surface domains,BC,DE and HI loops of the viruses may play an important role in host determination.