High-molecular-weight renin converting enzyme from dog kidney: detection and fractionation.
Renal cortical high-molecular-weight renin (Mw:60,000) of the dog is a complex of renin (low-molecular-weight renin; Mw:40,000) and a renin binding protein. We detected an enzyme-like substance that catalyzes the conversion from high- into low-molecular-weight renin. When the renal cortical extract was added to the high-molecular-weight renin and the preparation incubated at 37 degrees C for 30 min, the high-molecular-weight renin was converted into the low-molecular-weight form. No such conversion occurred in the case of renal medullary extract. This converting substance was fractionated using concanavalin A Sepharose, 70% ammonium sulfate saturation and DEAE-cellulose chromatography. The converting activity was inhibited by potassium tetrathionate, N-ethylmaleimide and 5,5'-dithiobis-(2-nitrobenzoic acid). These events suggest that this substance is an enzyme possessing sulfhydryl moieties. However, a cathepsin B inhibitor leupeptin did not affect the activity. Accordingly, the high-molecular-weight renin converting enzyme, which is sensitive to sulfhydryl oxidation, may explain the mechanism of interconversion between high- and low-molecular-weight renin involving the oxidation-reduction of tissue sulfhydryl groups.
D000818:Animals; D002238:Carbohydrate Epimerases; D002352:Carrier Proteins / Q000378:metabolism; D002401:Cathepsin B; D002403:Cathepsins / Q000378:metabolism; D002848:Chromatography, DEAE-Cellulose; D002851:Chromatography, High Pressure Liquid; D003546:Cysteine Endopeptidases; D004285:Dogs; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D007672:Kidney Cortex / Q000201:enzymology*; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000494:pharmacology; D012083:Renin / Q000378:metabolism*
D002352:Carrier Proteins; D011480:Protease Inhibitors; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; D012083:Renin; D002238:Carbohydrate Epimerases; C024519:N-acyl-D-glucosamine 2-epimerase