OCCURRENCE OF REDUCING TERMINAL N-ACETYLGLUCOSAMINE 3-SULFATE AND FUCOSYLATED OUTER CHAINS IN ACIDIC N-GLYCANS OF PORCINE ZONA-PELLUCIDA GLYCOPROTEINS

Structures of acidic N-glycans released from porcine zona pellucida gl ycoproteins by hydrazinolysis were studied. The results indicated that the acidic glycans are of mono- to tetraantennary complex-type with a nd without N-acetyllactosamine repeating units. Sulfated residues are not only located at the C-6 position of GlcNAc included in the N-acety llactosamine repeating units, but also at the C-6 position of GlcNAc i n the non-repeated antennae and at the C-3 position of reducing termin al GlcNAc residue. Analysis of the oligosaccharide fragments released by endo-P-galactosidase digestion and by hydrazine/nitrous acid treatm ent also revealed that various sulfated and non-sulfated forms of fuco sylated structures such as Fuc alpha 1 --> 2Gal beta 1 --> 4(+/- SO3- --> 6)GlcNAc (type 2H), Gal beta 1 --> 4(Fuc alpha 1 --> 3)(+/- SO3- - -> 6)GlcNAc(Le(x)) and Fuc alpha 1 --> 3 or 4(+/- SO3- --> 6)GlcNAc, a re expressed in the repeated outer chain moieties.