The use of lectin affinity columns for selection of precursor or fully glycosylated forms of glycoprotein gD1 of herpes simplex virus type 1.

Several lectins were examined for their ability to bind to the glycoprotein gD1 polypeptide from Vero cells infected by herpes simplex virus type 1 (HVS-1), strain KOS. At least four distinct forms of gD1 (1, 2, 3 and 4), ranging in size from 59K to 52K, were resolved by SDS-10% polyacrylamide gel electrophoresis. Wheat germ agglutinin (WGA) did not bind to any of these forms, suggesting that if any sialic residues are present in the carbohydrate moieties of gD1, they are not available for binding to WGA. The entire population of forms 1 and 2 (approximately 59K) bound to castor bean-120 (CB-120) lectin affinity columns, suggesting the presence of terminal galactose residues on the mature and more fully glycosylated carbohydrate moieties of gD1. The forms 3 and 4, representing precursor gD1 molecules, did not bind. The majority of forms 2 and 4, and a portion of form 3 bound to lentil lectin, suggesting the presence of fucose and alpha-linked mannosyl residues on these molecules. A gD1-specific, high molecular weight species (120-125K) was detected in the lentil lectin-binding fraction but not in the fraction bound to CB-120 lectin or in the original infected-cell extract. The results indicated that lectin affinity chromatography, using lentil and CB-120 lectins, is useful as an initial step for the selection and purification of the individual glycosylated forms of gD1.