Plasmin-treated low density lipoproteins: polypeptide analyses and metabolism by cultured smooth muscle cells.
Plasmin, generated by the interaction of urokinase with plasminogen, degraded the apoprotein B moiety of human low density lipoprotein to yield distinct high moleculr weight intermediates under conditions where only a small fraction (less than 3%) of the protein was hydrolyzed to trichloroacetic acid-soluble products. The molecular weights of these intermediates were between 60 000 and 200 000 as estimated by SDS-polyacrylamide electrophoresis. Trypsin treatment yielded fragments of similar size to those obtained with plasmin. When enzyme-treated low density lipoproteins were added to bovine aortic smooth muscle cells in culture, the receptor-binding, and rates of internalization and degradation were no different from those obtained in the case of native low density lipoproteins.
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002478:Cells, Cultured; D005341:Fibrinolysin / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008970:Molecular Weight; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010455:Peptides / Q000032:analysis*; D014357:Trypsin / Q000494:pharmacology
D008077:Lipoproteins, LDL; D010455:Peptides; D014357:Trypsin; D005341:Fibrinolysin