Structural elucidation of the disulfated oligosaccharide from bovine lutropin.
The Asn-linked oligosaccharides of the pituitary hormone lutropin (LH) contain both sulfate and GalNAc. Bovine pituitary explants incorporate [3H]glucosamine, [3H]mannose, [3H]fucose, and [35S]sulfate into the Asn-linked oligosaccharides of LH. Endoglycosidase F or N-glycanase releases the [3H]glucosamine- and [3H]mannose-labeled oligosaccharides from the protein, which resolve on anion-exchange high pressure liquid chromatography as neutral (S-0), mono- (S-1), and disulfated (S-2) species. Based on sequential enzyme digestion, methylation, periodate oxidation, and nuclear magnetic resonance studies, the proposed structure for S-2 is as follows: formula see text. Sulfate is confined to position 3 or 4 of GalNAc based on periodate and methylation data and can be removed by methanolysis. The presence of beta-linked GalNAc at a position typically occupied by Gal has not previously been observed.
D000818:Animals; D002240:Carbohydrate Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D005643:Fucose / Q000032:analysis; D005944:Glucosamine / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D007986:Luteinizing Hormone / Q000032:analysis*; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008745:Methylation; D009844:Oligosaccharides / Q000032:analysis*; D010504:Periodic Acid; D010902:Pituitary Gland / Q000378:metabolism; D013431:Sulfates / Q000032:analysis
D009844:Oligosaccharides; D013431:Sulfates; D010504:Periodic Acid; D005643:Fucose; D007986:Luteinizing Hormone; C009288:metaperiodate; D006026:Glycoside Hydrolases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D005944:Glucosamine