Analysis of virus protein heterogeneity among group B coxsackie viruses using a "mini" two-dimensional gel electrophoresis system

Abstract

The application of a small format two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) system to the study of protein heterogeneity among group B coxsackie virus (CVB) isolates is described. Under the conditions of electrophoresis developed during this study, protein samples could be processed within 7 h and up to 300 intracellular proteins were resolved from uninfected HEp-2 cell lysates. 2D-PAGE was used to characterise the intracellular proteins of clinical CVB isolates of serotypes 4 and 5. Intracellular proteins from virus-infected cells were radiolabelled using a pulse-chase protocol under conditions which promoted inhibition of cellular protein synthesis. Depending on the CVB serotype up to 11 intracellular virus proteins were identified, ranging in molecular weight between 14,000 and 54,000. Although the overall two-dimensional protein profiles were characteristic for the two CVB serotypes, within a CVB serotype there was some heterogeneity of the virus proteins, mainly affecting the proteins' net charge. The sensitivity of 2D-PAGE in detecting subtle differences in virus proteins combined with the convenience of the small gel format makes this a suitable approach for the study of the molecular epidemiology of human virus pathogens.