Characterization of a sulfotransferase from human airways responsible for the 3-O-sulfation of terminal galactose in N-acetyllactosamine-containing mucin carbohydrate chains.
A galactose 3-O-sulfotransferase activity able to transfer a sulfate group from adenosine 3'-phosphate 5'-phosphosulfate to methyl galactosides or terminal N-acetyllactosamine-containing carbohydrate chains from human respiratory mucins was characterized in microsomal fractions prepared from human respiratory mucosa. The reaction products, methyl alpha- or beta-galactose 3-sulfate and three oligosaccharide alditols containing the sequence HSO3-3Gal beta 1-4GlcNAc beta 1-6GalNAc-itol were identified by high performance anion-exchange chromatography. Using methyl beta-galactoside as a substrate, the optimum activity was obtained with 0.1% Triton X-100, 30 mM NaF, 20 mM Mn2+, and 10 mM AMP in a 30 mM 2-(N-morpholino)ethanesulfonic acid buffer at pH 6.1. The apparent Km for methyl beta-galactoside and for adenosine 3'-phosphate 5'-phosphosulfate were observed at 0.69 x 10(-3) M and at 4 x 10(-6) M respectively. This sulfotransferase is different from that responsible for sulfatide synthesis.
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000606:Amino Sugars; D001667:Binding, Competitive; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005690:Galactose; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008168:Lung / Q000201:enzymology*; D008175:Lung Neoplasms / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology*; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry* / Q000378:metabolism*; D009092:Mucous Membrane / Q000201:enzymology; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D012969:Sodium Fluoride / Q000494:pharmacology; D013379:Substrate Specificity; D015238:Sulfotransferases / Q000378:metabolism*
D000606:Amino Sugars; D009077:Mucins; D009844:Oligosaccharides; C000458:N-acetyllactosamine; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D012969:Sodium Fluoride; D015238:Sulfotransferases; C097036:galactose 3-O-sulfotransferase; D005690:Galactose