The isolation and characterization of rat sublingual mucus-glycoprotein.
A purified glycoprotein, designated RSL-major, was isolated from the rat sublingual gland by means of the procedure of Tettamanti and Pigman. It was found to be homogeneous by analytical ultracentrifugation, to have a mol. wt. of 2-2 times 10-6, and to contain 81 percent (W/W) of carbohydrate, which consists mainly of sialic acid, 2-acetamido-2-deocy-D-glucose, 2-acetamido-2-deocy-D-galactose, and D-galactose in the molar ratio of 1.4:1.4:1.0:1.5; small amounts of fucose and mannose [1.2 and 2.8 percent (W/W), respectively] were also present. The sialic acid residues were resistant to the action of V. cholerae neuraminidase. This resistance was completely abolished by removal of the O-acetyl groups contained in the sialic acid. The sialic acid in RSL-major appeared to be a mixture of N-acetyl-4-O-acetyl- and N-acetyl-4, 7(8)-di-O-acetylneuraminic acids. The carbohydrate to protein attachment of RSL-major was shown, by alkaline beta-elimination reaction, to consist of an O-glycosyl linkage between 2-acetamido-2-deoxy-D-galactosyl residues in the oligosaccharide chains and seryl and threonyl residues in the protein core. The average oligosaccharide, contained in RSL-major, was postulated to be a heptasaccharide. A second material, designated RSL-minor, and also isolated from the ratsublingual gland, was obtained as a mixture of glycoprotein(s) and hydroxylapatite gel, and was not purified further.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001665:Binding Sites; D005643:Fucose / Q000032:analysis; D005688:Galactosamine / Q000032:analysis; D005690:Galactose / Q000032:analysis; D005944:Glucosamine / Q000032:analysis; D006023:Glycoproteins / Q000302:isolation & purification; D008358:Mannose / Q000032:analysis; D008970:Molecular Weight; D009093:Mucus / Q000032:analysis*; D009439:Neuraminidase; D011485:Protein Binding; D051381:Rats; D012794:Sialic Acids / Q000032:analysis; D013361:Sublingual Gland / Q000032:analysis*; D014734:Vibrio cholerae / Q000201:enzymology
D000596:Amino Acids; D006023:Glycoproteins; D012794:Sialic Acids; D005643:Fucose; D005688:Galactosamine; D009439:Neuraminidase; D005944:Glucosamine; D008358:Mannose; D005690:Galactose