Title : Isolation and characterization of
the O-glycan chain of the human
vitamin-D binding protein
Abstract :
- On a highly purified preparation, the structure of the carbohydrate chain of the human vitamin D-binding protein was investigated and two genetic forms of this protein were considered ( Gc 2 and Gc 1 proteins )
- It was found that only the Gc 1 protein ( Gc1a isoform ) was glycosylated, the glycan moiety representing about 1% of the protein
- The structure of this O-glycosidically linked glycan was determined to be: Neu Ac alpha (2 leads to 3) Gal beta (1 leads to 3) GaINAc alpha (1 leads to 0) Ser (or Thr )
- A tetrasaccharidic O-glycan with two N-acetylneuraminic residues was also characterized
- The vitamin D-binding protein is a rare example of a serum protein O-glycosylated only on some genetic forms