Kinetic properties of mitochondrial ATPase during isoproterenol-induced cardiomyopathy.
1. The kinetic characteristics of the ATP hydrolysis by membrane-bound and Triton X-100 solubilized mitochondrial ATPase, during the isoproterenol-induced cardiomyopathy, were investigated. 2. An increase in the inhibitory action of the oligomycin, a decrease in the affinity of the ATP binding sites and an increase of both activation energy and rate of thermal inactivation were observed for mitochondrial ATPase. 3. The possibility that the changes described are related to the modifications of the active configuration of mitochondrial ATPase, during the isoproterenol-induced cardiomyopathy, is discussed.
Curti
C
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Departamento de Física e Química, Faculdade de Ciências Farmacêuticas-USP, Ribeirão Preto, S.P., Brasil.
Uyemura
S A
SA
Grecchi
M J
MJ
Leone
F A
FA
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D009202:Cardiomyopathies / Q000139:chemically induced* / Q000201:enzymology / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007545:Isoproterenol / Q000633:toxicity*; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D003902:Detergents; D011092:Polyethylene Glycols; D000255:Adenosine Triphosphate; D017830:Octoxynol; D000251:Adenosine Triphosphatases; D007545:Isoproterenol