Abstract
The major envelope glycoprotein of bovine leukemia virus was isolated by lectin-bound Sepharose and DEAE-cellulose column chromatography. This protein had a MW of about 51,000 and lacked detectable immunological cross-reactivity with glycoproteins of other oncornaviruses. Sera obtained from 100% of cattle examined with clinically diagnosed lymphosarcoma contained high-titered antibody to 125I-labeled bovine leukemia virus glycoprotein, but sera from animals in a disease-free herd were antibody negative.