The Major Polypeptides of the Murine‐Mammary‐Tumor Virus Isolated by Plant‐Lectin Affinity Chromatography

Abstract
Solubilized polypeptides of the murine mammary tumor virus were chromatographed on a column of immobilized concanavalin A. The unbound viral material was rechromatographed on phosphocellulose, resulting in the isolation of the major internal proteins with a MW of 28,000 (p28) and 12,000 (p12), respectively. The adsorbed glycopolypeptides after elution with methyl .alpha.-D-mannopyranoside were subjected to gel filtration. The major glycoprotein with a MW of 52,000 (gp52) was obtained in an almost pure form. A considerable part of gp52 elutes together with a glycoprotein with a MW of 36,000 (gp36), suggesting that in addition to the free form of gp52 a complex exists of gp52 plus gp36.