Molecular forms of cathepsin D in coated vesicle preparations.
We have studied the polypeptide pattern of cathepsin D associated with coated vesicle fractions prepared from human placenta. In these fractions cathepsin D was about 35-fold enriched in the precursor polypeptides as compared to the unfractionated tissue extract. The enrichment was more prominent if the vesicles were fractionated in the presence of Triton X-100. Adsorption of exogenously added metabolically labelled cathepsin D precursor to the fractionated material was negligible. It is likely that the precursor and may be also the mature cathepsin D polypeptides are present in the matrix of the coated vesicles. This finding substantiates the idea that coated vesicles participate in the transport of newly synthesized cathepsin D into the lysosomes.
D002402:Cathepsin D; D002403:Cathepsins / Q000302:isolation & purification / Q000378:metabolism*; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D003034:Coated Pits, Cell-Membrane / Q000201:enzymology* / Q000648:ultrastructure; D011992:Endosomes / Q000201:enzymology*; D005260:Female; D006801:Humans; D008247:Lysosomes / Q000201:enzymology; D008854:Microscopy, Electron; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy
D002403:Cathepsins; D002402:Cathepsin D