Evidence for a single glycan moiety in rabbit serum transferrin and location of the glycan within the polypeptide chain.

The sequential removal of N-acetylneuraminic acid from rabbit serum transferrin has been followed by urea-polyacrylamide gel electrophoresis. The electrophoretic pattern is consistent with the presence of a single biantennary glycan chain. From the amino acid sequence of the carbohydrate-containing cyanogen bromide fragment we have shown that the glycan is attached to an asparaginyl side chain at a position equivalent to residue 491 in the sequence of human serum transferrin.