Structural proteins of equine arteritis virus

Summary Polyacrylamide gel electrophoresis of purified and solubilized equine arteritis virus (EAV) revealed nine structural proteins. Two of these proteins with molecular weights of 15,000 (VP7) and 13,000 (VP8) daltons are considered as major. The molecular weights of the seven minor proteins ranged between 72,000 and 10,500 daltons.The core fraction of the virion was dissociated from the envelope fraction by sucrose gradient centrifugation of virus treated with the nonionic detergent Nonidet P40 and phospholipase C. The core fraction contained RNA and one major protein (VP8), whereas the envelope contained one major protein (VP7) and the seven minor proteins. Six of the nine proteins (VP1 through VP6) were labeled with¹⁴C-glucosamine and are thus glycoproteins. VP8, a nonglycoprotein associated with the core fraction, is apparently the nucleoprotein of EAV.