Significant amount of multicatalytic proteinase identified on membrane from human erythrocyte.
Multicatalytic proteinase (MCP) was solubilized from human erythrocyte membrane with 0.1% Triton X-100 and purified to homogeneity using a combination of DEAE-cellulose, hydroxylapatite, and Ultrogel AcA34 chromatographies. This membranous MCP had similar properties to MCP purified in parallel from the cytosol. Both MCPs had a molecular mass of 570 kDa, were composed of apparently nine subunits of 22-36 kDa and had trypsin- and chymotrypsin-like activities. These activities were latent and required heating for the induction. However, slight differences were observed in the effects of reagents (DFP, monoiodoacetic acid, Mg2+, and Ca2+) between membranous and cytosolic MCP. The amount of MCP identified on membranes was estimated to be three-quarters or one-half of that found in the cytosol based on its trypsin- or chymotrypsin-like activity, respectively.
Department of Fisheries, Faculty of Agriculture, Kyoto University.
M
M
Kinoshita
T
T
Hamakubo
I
I
Fukui
T
T
Murachi
H
H
Toyohara
D002384:Catalysis; D002848:Chromatography, DEAE-Cellulose; D003546:Cysteine Endopeptidases / Q000097:blood*; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000201:enzymology*; D006801:Humans; D007202:Indicators and Reagents; D009097:Multienzyme Complexes / Q000097:blood*; D046988:Proteasome Endopeptidase Complex; D012967:Sodium Dodecyl Sulfate; D013696:Temperature
D007202:Indicators and Reagents; D009097:Multienzyme Complexes; D012967:Sodium Dodecyl Sulfate; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex