Significant Amount of Multicatalytic Proteinase Identified on Membrane from Human Erythrocyte

• Published in: Journal of biochemistry (Tokyo) Vol. 107; no. 3; pp. 440 - 444
• Main Authors: Kinoshita, Masato, Hamakubo, Takao, Fukui, Ichiro, Murachi, Takashi, Toyohara, Haruhiko
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.03.1990
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Catalysis; Chromatography, DEAE-Cellulose; Cysteine Endopeptidases - blood; Cytosol - enzymology; Electrophoresis, Polyacrylamide Gel; Enzymes and enzyme inhibitors; Erythrocyte Membrane - enzymology; Fundamental and applied biological sciences. Psychology; Humans; Hydrolases; Indicators and Reagents; multicatalytic proteinase; Multienzyme Complexes - blood; plasma membranes; Proteasome Endopeptidase Complex; Sodium Dodecyl Sulfate; Temperature; Human; Purification; Proteinase; Plasma membrane; Red blood cell; Polymer; Catalyst activity; Cytosol; Chromatography
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a123064

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.