Studies on Vi antigen. IV. Physicochemical characterization of Vi antigens isolated from V form Enterobacteriaceae.

Abstract

Summary The Vi antigen was isolated by the same method from 3 generically different bacterial species, viz. E. coli, P. ballerup and S. typhosa . A comparison was made of some of the chemical and physical properties of the purified antigens. These include nitrogen, acetyl groups, neutral equivalent, viscosity, infrared spectra, electrophoretic mobilities and sedimentation constants. Except for significant differences in viscosity, the analytical values for the three isolated antigens were similar. The average molecular weight of the Vi antigen derived from E. coli was estimated at 1,000,000.