Analysis of the site-specific asparagine-linked glycosylation of recombinant human coagulation factor VIIa by glycosidase digestions, liquid chromatography, and mass spectrometry.

The two asparagine-linked glycosylation sites of recombinant coagulation factor VIIa have been characterized by glycosidase digestions, size-exclusion chromatography (SEC), and mass spectrometry (MS). Nine structures were characterized as core fucosylated bi-and triantennary structures with 0-3 sialic-acid residues which were alpha 2-3 linked to galactose exclusively. Three of the structures had one or two galactose residues substituted by N-acetylgalactosamine. Significant differences were found between the oligosaccharide profiles for the two glycosylation sites in rFVIIa. At Asn322, the degree of sialylation was lower and higher amounts of structures containing N-acetylgalactosamine were found compared to Asn145.