Binding of cathepsin D to the mannose receptor on rat peritoneal macrophages.
Adherent cultures of rat peritoneal macrophages secrete lysozyme and the lysosomal marker enzymes beta-glucuronidase, beta-N-acetylglucosaminidase and acid phosphatase; the levels of secreted lysosomal cathepsin D, however, were found to be insignificant. Incubation of the cells at 4 degrees C for 15 min with yeast mannan or with 50 mM mannose, methyl alpha-glucopyranoside, or N-acetylglucosamine caused the concentration of cathepsin D in the culture medium to increase 30-40-fold; mannose-6-phosphate had no effect. 125I-labeled cathepsin D was prepared and the binding constant to the macrophage cell surface was determined to be KD = 27 nM. The data suggest that cathepsin D binds to the mannose receptor of macrophages and that binding to this receptor is not in equilibrium with the bulk medium.
Department of Chemistry, University of Illinois, Chicago 60680.
P R
PR
Young
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Karanutilake
A P
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Zygas
D000117:Acetylglucosamine / Q000494:pharmacology; D000818:Animals; D002402:Cathepsin D / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002478:Cells, Cultured; D037181:Lectins, C-Type; D008247:Lysosomes / Q000201:enzymology; D008264:Macrophages / Q000201:enzymology / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism* / Q000494:pharmacology; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008360:Mannosephosphates / Q000494:pharmacology; D008757:Methylglucosides / Q000494:pharmacology; D010529:Peritoneal Cavity; D051381:Rats; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000378:metabolism*
D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008360:Mannosephosphates; D008757:Methylglucosides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C027693:mannose-6-phosphate; C027020:methylglucoside; D002402:Cathepsin D; D008358:Mannose; D000117:Acetylglucosamine