1 - Analysis of Protein Constituents of Viruses

Abstract

Publisher Summary This chapter focuses on protein methodology with particular attention to micromethods and to proteins that tend to associate to high molecular weight complexes. It discusses the chemical and physical methods for characterization of virus proteins. The chemical methods used for characterization of virus proteins that are discussed in the chapter are amino acid analysis, end-group analysis, and modification of functional groups. The automatic analysis has become a primary tool in the course of purification and in the structural analysis of peptides and proteins. If an amino acid analyzer is not available, amino acid analysis can conveniently be performed by dinitrophenylating the residue after evaporating the acid off the protein hydrolyzate in the usual manner. The physical methods used for characterization of virus proteins that are discussed in the chapter include electrophoresis, gel filtration, ultracentrifugation, and zonal centrifugation on density gradients. Gel filtration is a procedure in which separation is based to a large extent upon differences in molecular size. Three major classes of materials that are currently in use are agarose, polyacrylamide, and dextran gels. Ultracentrifuge is particularly suited to quantitative studies on the size and homogeneity of macromolecules in solution, and it was the introduction of ultracentrifugation that led to general acceptance of the concept of proteins as macromolecules of defined size.