title: [Endogenous inhibitor of cysteine proteases from the human kidney].
abstract: A thermo- and acid stable inhibitor of cysteine proteinases was isolated from the human kidney by successive procedures--acid fractionation, gel-filtration on Sephadex G-75, affinity chromatography on papain-sepharose. The final purification factor was 650 fold. The inhibitor molecular weight was equal to 12 kDa. The values of Ki measured by different methods are (7.9-9.4) X 10(-4) M for papain and (7.1-8.0) X 10(-10) M for purified human kidney cathepsin B. In experiments with papain, inhibitor kass and kd were 1.1 X 10(6) M-1 s-1 and 9.0 X 10(-4) s-1, respectively. The inhibitor did not influence the trypsin activity, its properties being similar to those of related thermo- and acid-stable inhibitors from other human and animal tissues.
mesh_terms: D002850:Chromatography, Gel; D015853:Cysteine Proteinase Inhibitors; D004795:Enzyme Stability; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D011480:Protease Inhibitors / Q000302:isolation & purification*; D011506:Proteins / Q000302:isolation & purification*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D011480:Protease Inhibitors; D011506:Proteins
vernacular_title: Endogennyĭ ingibitor tsisteinovykh proteinaz iz pochki cheloveka.