Effect of a proteinase inhibitor, aprotinin, on brush border membrane associated aminopeptidase of human kidney cortex.
In order to study the influence of the basic proteinase inhibitor aprotinin (Trasylol) on renal tubular alanine-aminopeptidase (E.C.3.6.11-), a brush border fraction was prepared from human kidney cortex by differential centrifugation. Incubation of brush border fragments, rich in membrane bound alanine-aminopeptidase, resulted in an activation of the enzyme. However, aminopeptidase, which was cleaved off from the membranes by limited proteolysis and subsequently purified by Concanavalin A-affinity chromatography exhibited activation by low but inhibition by higher concentration of aprotinin. Thus inhibition was associated with presence of the solubilized form of the brush border enzyme. On the other hand, as was shown by quantitative electroimmunoassay, formation of antigen-antibody complexes between soluble renal aminopeptidase and its specific rabbit antibody was not changed by the basic polypeptide.
D000626:Aminopeptidases / Q000276:immunology / Q000378:metabolism*; D007611:Aprotinin / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000201:enzymology* / Q000648:ultrastructure; D008871:Microvilli / Q000201:enzymology; D013268:Stimulation, Chemical
D007611:Aprotinin; D000626:Aminopeptidases