Sialic acid patterns in N‐linked carbohydrate chains. Structural analysis of the N‐acetyl‐/N‐glycolyl‐neuraminic‐acid‐containing N‐linked carbohydrate chains of bovine fibrinogen

The N ‐linked carbohydrate chains of bovine fibrinogen have been released by peptide‐ N 4 ‐( N ‐acetyl‐β‐glucosaminyl)asparagine amidase‐F, fractionated by FPLC and HPLC procedures and characterized by 500/600‐MHz 1 H NMR spectroscopy. Evidence is presented for the native sialic acid patterns, involving the occurrence of α2 → 6‐linked N ‐acetyl‐ and N ‐glycolylneuraminic acid residues in the terminal position of the di‐antennary carbohydrate chains. Details are included of minor oligosaccharides containing Neu5Acα2 → 3Galβ 1→ 4/β1 → 3GlcNAc β1 → structural elements, which have not been previously described in this glycoprotein.