title: Rat cauda epididymal fluid is a mucus.
abstract: Immobilin, the highly viscoelastic glycoprotein isolated from rat cauda epididymal fluid, exhibits all of the key biochemical characteristics of a mucin: 1) it has a very high molecular weight (will not pass through a 10(6) dalton cut-off filter; 2) it contains 56% carbohydrate, with low or undetectable levels of mannose, xylose and uronic acid; 3) the carbohydrates (primarily galactose, N-acetylglucosamine and N-acetylgalactosamine) are arranged in short, oligosaccharide chains (4-20 monosaccharides per chain); 4) these oligosaccharide chains can be cleaved by NaOH in the presence of NaBH4, suggesting O-glycosidic linkages; and 5) the protein core is pronase-resistant. Immobilin, however, contains no detectable sialic acid, and 67% of the oligosaccharides are uncharged, indicating that immobilin is less acidic than most other mucins.
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000032:analysis; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002621:Chemistry; D002852:Chromatography, Ion Exchange; D004548:Elasticity; D004822:Epididymis / Q000032:analysis*; D006023:Glycoproteins / Q000302:isolation & purification* / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D009093:Mucus / Q000032:analysis*; D009844:Oligosaccharides / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D014783:Viscosity
chemical_list: D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D009844:Oligosaccharides; C039654:immobilin protein, rat