title: Oligosaccharides on cathepsin D from porcine spleen.
abstract: Cathepsin D from porcine spleen contained mannose (3.3%), glucosamine (1.4%), and mannose 6-phosphate (0.08%). Essentially all of the oligosaccharides of cathepsin D could be released by endo-beta-N-acetylglucosaminidase H, pointing to oligomannoside types of structures. Three neutral oligosaccharide fractions, containing 5, 6, and 7 mannose residues, respectively, were isolated by gel permeation chromatography on Bio-Gel P-2. Studies using exoglycosidase digestions and 500-MHz 1H NMR spectroscopy revealed that their structures are [Man alpha 1 leads to 2]0 or 1 Man alpha 1 leads to 6[Man alpha 1 leads to 3]Man alpha 1 leads to 6[Man alpha 1 leads to 2)0 or 1 Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4 GlcNAc. These structures are identical to what have recently been proposed by Takahashi et al. for the major oligosaccharide units of cathepsin D from the same source (T. Takahashi, P. G. Schimidt, and J. Tang (1983) J. Biol. Chem. 258, 2819-2930), except for the occurrence of two isomeric oligosaccharides containing six mannoses. Only a part (3.4%) of the oligosaccharides were acidic, containing phosphates in monoester linkage. The phosphorylated oligosaccharides also consisted of oligomannoside-type chains which were analogous to, but more heterogeneous in size than the neutral oligosaccharides. Cathepsin D was bound to a mannose- and N-acetylglucosamine-specific lectin (mannan-binding protein) isolated from rabbit liver with the Ki value of 5.4 X 10(-6) M.
mesh_terms: D000118:Acetylglucosaminidase; D000818:Animals; D001667:Binding, Competitive; D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000032:analysis; D002352:Carrier Proteins / Q000378:metabolism; D002402:Cathepsin D; D002403:Cathepsins / Q000032:analysis*; D002850:Chromatography, Gel; D037222:Collectins; D006600:Hexosephosphates / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000032:analysis; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D009844:Oligosaccharides / Q000032:analysis*; D013154:Spleen / Q000032:analysis*; D013552:Swine
chemical_list: D002241:Carbohydrates; D002352:Carrier Proteins; D037222:Collectins; D006600:Hexosephosphates; D009844:Oligosaccharides; D000118:Acetylglucosaminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D002403:Cathepsins; D002402:Cathepsin D; D008358:Mannose