THE STRUCTURAL-ANALYSIS OF THE O-GLYCANS OF THE JACALIN-BOUND RABBIT IMMUNOGLOBULIN-G

Rabbit immunoglobulin G (IgG) is a sialoglycoprotein (2.4% carbohydrat e), containing both N-glycolyl (Neu5Gc) and N-acetyl (Neu5Ac) neuramin ic acids in a ratio of 87:13. A small fraction of rabbit IgG (about 25 % of total IgG) bound to jacalin as demonstrated by affinity chromatog raphy. The jacalin-bound rabbit IgG contained O-linked glycans which w ere liberated from the protein by beta-elimination and isolated. Two O -glycan structures were determined by H-1-NMR spectroscopy, as being N eu5Gc(alpha 2-3)-Gal(beta 1-3)-GalNAc-ol and Neu5Ac(alpha 2-3)-Gal(bet a 1-3)-GalNAc-ol in a ratio of 83:17.