ATP-activated, high-molecular-mass proteinase-I from rat skeletal muscle is a cysteine proteinase-alpha 1-macroglobulin complex.
From rat skeletal muscle tissue we have isolated and purified a proteolytic activity of molecular mass 750 kDa. The enzyme, designated 'proteinase I', which has been found to be located in capillaries of skeletal muscle tissue, catalyzes the hydrolysis of Z-Phe-Arg-MCA and [14C]methylcasein and this process is activated about 2-fold by ATP. As judged by SDS-polyacrylamide gel electrophoresis the subunit pattern of 'proteinase I' is similar to alpha-macroglobulin. Immunoelectrophoretic analyses of 'proteinase I' with antisera to rat alpha 1-macroglobulin, alpha 2-macroglobulin, and rat liver cathepsins reveal that this high-molecular-mass proteinase is a complex of alpha 1-macroglobulin and the cysteine proteinases cathepsin B, H and L. A similar 'proteinase' has been isolated from rat serum. Two ATP-activated high molecular-mass proteinases that have been previously identified in liver and heart muscle by other investigators equally show a positive immunological reaction with the antiserum raised against 'proteinase I'. From these data, together with results presented in an accompanying paper (Kuehn, L., Dahlmann, B., Gauthier, F. and Neubauer, H.-P. (1989) Biochim. Biophys. Acta 991, 263), we conclude that the ATP-stimulated high-molecular-mass proteolytic activity is partly due to the presence of a complex of alpha-macroglobulin and cysteine proteinases.
Dahlmann
B
B
Biochemische Abteilung, Diabetes Forschungsinstitut, Düsseldorf, F.R.G.
Kuehn
L
L
Heinrich
P C
PC
Kirschke
H
H
Wiederanders
B
B
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D007122:Immunoelectrophoresis; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D051381:Rats; D000511:alpha-Macroglobulins / Q000302:isolation & purification* / Q000378:metabolism
D046911:Macromolecular Substances; D000511:alpha-Macroglobulins; D000255:Adenosine Triphosphate; C059980:ATP-activated high molecular mass proteinase I; D003546:Cysteine Endopeptidases