Immunochemical studies of infectious mononucleosis. VII. Isolation and partial characterization of a glycopeptide from bovine erythrocytes.

The major sialoglycopeptide released from bovine erythrocytes by papain has been purified and characterized. The glycopeptide contains 82% by weight carbohydrate in molar ratios of galactose - 5.5:N-acetylglucosamine - 3.6:sialic acid - 2.6:N-acetylgalactosamine - 1.0. The carbohydrate and amino acid composition is quite different from the glycoprotein extracted from bovine erythrocyte stroma with hot 75% ethanol. The glycopeptide is devoid of reactivity with Paul-Bunnell heterophile antibody of infectious mononucleosis - an activity expressed to high degree on the bovine erythrocyte and associated with glycoprotein. The glycopeptide does react, however, with another antibody found in infectious mononucleosis as well as most normal human sera tested.