Single Major Polypeptide of a Calicivirus: Characterization by Polyacrylamide Gel Electrophoresis and Stabilization of Virions by Cross-Linking with Dimethyl Suberimidate.

摘要

A calicivirus, San Miguel sea lion virus serotype 4, isolate 15FT, externally labeled with I(125) was shown by gel electrophoresis to possess a single major polypeptide. The polypeptide migrated anomalously upon electrophoresis in two sodium dodecyl sulfate (SDS) systems; more slowly than bovine serum albumin in a continuous phosphate-buffered system and more rapidly than bovine serum albumin in a discontinuous system. Estimated molecular weights in the two systems were approximately 71,000 and 64,000, respectively. There was no clear evidence for a minor virion polypeptide. Treatment of purified San Miguel sea lion virions with dimethyl suberimidate, a cross-linking reagent, preserved virion integrity during long-term storage at 4 C. Oligomeric species of the polypeptide were observed upon electrophoresis of products from cross-linked virions. Based upon a preferred polypeptide molecular weight estimate of 71,000 and distribution of oligomeric species, a calicivirion model with 120 monomeric protein units is proposed as an alternative to a 180-unit model. (Author)