Studies on the mechanism of oxidative phosphorylation. Catalytic site cooperativity in ATP synthesis.
1985; Elsevier BV; Volume: 260; Issue: 27 Linguagem: Inglês
10.1016/s0021-9258(17)38584-8
ISSN1083-351X
AutoresAkemi Matsuno‐Yagi, Youssef Hatefi,
Tópico(s)RNA and protein synthesis mechanisms
ResumoOxidative phosphorylation catalyzed by bovine heart submitochondrial particles appears to exhibit negative cooperativity with respect to [ADP] and positive cooperativity in catalysis.Eadie-Hofstee plots (v/[ S I uersus u ) of the kinetics of oxidative phosphorylation at the variable ADP concentration range of 1-1200 WM were curvilinear and could be analyzed for two apparent KiDp values differing by one order of magnitude, and two apparent V , , values.The KiDp values with either NADH or succinate as the respiratory substrate were in the ranges of 10 and 100 p ~, and the Vmax values in nmol of ATP formed.min-l(mg of protein)" were, respectively, 500 and 1840 when NADH was the oxidizable substrate, and 550 and 100 when succinate was the energy source.Site-site cooperativity of the ATP synthase, which is a central feature of current theories for the mechanism of oxidative phosphorylation, has been well-documented for ATP hydrolysis by isolated F1-ATPase, but never before demonstrated for mitochondrial ATP synthesis.
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