Title :
High-mannose-type oligosaccharides from human placental
arylsulfatase A are core fucosylated as confirmed by MALDI MS. Despite numerous studies on
arylsulfatase A , the structure of
its glycans is not well understood
Abstract :
- It has been shown that the concentration of arylsulfatase A increases in the body fluids of patients with some forms of cancer, and the carbohydrate component of arylsulfatase A synthesized in tumor tissues and transformed cells undergoes increased sialylation , phosphorylation and sulfation
- To understand the significance of any changes in the glycosylation of arylsulfatase A in cancer, it is important to know the structure of its carbohydrate component in normal tissue
- In the present study we have analyzed carbohydrate moieties of human placental arylsylfatase A using sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE) followed by Western blotting on Immobilon P and on-blot deglycosylation using PNGase F for glycan release
- Profiles of N-glycans were obtained by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS)
- Oligosaccharides were sequenced using specific exoglycosidases, and digestion products were analyzed by MALDI MS and the computer matching of the resulting masses with those derived from a sequence database
- Fifty picomoles (6 microg) of arylsulfatase A applied to the gel were sufficient to characterize its oligosaccharide content
- The results indicated that human placental arylsulfatase A possesses only high-mannose-type oligosaccharides, of which almost half are core fucosylated
- In addition, there was a minor species of high-mannose-type glycan bearing six mannose residues with a core fucose.
- This structure was not expected since high-mannose-type oligosaccharides basically have not been recognized as a substrate for the alpha1,6-fucosyltransferase