Title :
Oligosaccharide structures present on
asparagine-289 of recombinant human
plasminogen expressed in a Chinese hamster ovary cell line
Abstract :
- The oligosaccharide structures linked to Asn289 of a recombinant (r) variant (R561S) human plasminogen ( HPg ) expressed in Chinese hamster ovary (CHO) cells, after transfection of these cells with a plasmid containing the cDNA coding for the variant HPg , have been determined
- Employing high-performance anion-exchange liquid chromatography mapping of the oligosaccharide units cleaved from the protein by glycopeptidase F , compared with elution positions of standard oligosaccharides , coupled with monosaccharide compositional determinations and analyses of sequential exoglycosidase digestions and specific lectin binding, we find that considerable microheterogeneity in oligosaccharide structure exists at this sole potential N-linked glycosylation site on HPg
- A variety of high-mannose structures, as well as bi-, tri-, and tetraantennary complex-type carbohydrate , has been found, in relative amounts of 1-25% of the total oligosaccharides
- The complex-type structures contain variable amounts of sialic acid (Sia), ranging from 0 to 5 mol/mol of oligosaccharide in the different glycan structures.
- Neither hybrid-type molecules, N-acetylglucosamine bisecting oligosaccharides, nor N-acetyllactosaminyl-repeat structures were found to be present in the complex-type carbohydrate pool in observable amounts
- Of interest, a significant portion of the Sia exists an outer arm structures in an (alpha 2,6) linkage to the penultimate galactose, a novel finding in CHO cell-directed glycosylation
- (ABSTRACT TRUNCATED AT 250 WORDS