Proteins of equine herpesvirus type 3. I. Polypeptides of the purified virion.

Enveloped virions of equine herpesvirus type 3 (EHV-3) were purified from the extracellular fluids of infected horse embryo fibroblast cell cultures (KyED) by sequential banding in dextran-10 and potassium tartrate density gradients. The preparations of purified virus consisted of enveloped herpesvirus particles with little extraneous cellular material demonstrable by electron microscopy or by overt addition of labeled cellular proteins prior to purification. Structural polypeptides of the purified EHV-3 virions were analyzed by electrophoresis in SDS-polyacrylamide slab gels cross-linked with N,N′-diallytartardiamide. Thirty-four polypeptides, ranging in molecular weight from 14 × 10³ to 220 × 10³ were resolved in Coomassie brilliant blue-stained electropherograms of the purified virions. Ten of these proteins were larger than 100 × 10³ and two were larger than 200 × 10³. A 148 × 10³ capsid protein was a major structural polypeptide of the EHV-3 virion. Coelectrophoresis of the proteins of EHV-3 virions with those of the genetically unrelated equine herpes-virus type 1 (EHV-1) revealed a similarity in size range and number of the virion structural proteins; however, the molecular weights and proportional composition of the majority of EHV-3 polypeptides differed significantly from those of the virion proteins of EHV-1.