Tightly bound adenosine diphosphate, which inhibits the activity of mitochondrial F1‐ATPase, is located at the catalytic site of the enzyme

FEBS Letters

Murataliev, M.B.¹  Kozlov, I.A.¹  Drobinskaya, I.Ye.¹  Vulfson, E.N.¹ 

[1] A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry. Moscow state University, Moscow 11989, USSR

关键词: Mitochondrial F1-ATPase;    Nucleotide binding;    ADP inhibition;    Phosphate binding;   

DOI  :  10.1016/0014-5793(85)80346-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The binding of one ADP molecule at the catalytic site of the nucleotide depleted F₁-ATPase results in a decrease in the initial rate of ATP hydrolysis. The addition of an equimolar amount of ATP to the nucleotide depleted F₁-ATPase leads to the same effect, but, in this case, inhibition is time dependent. The half-time of this process is about 30 s, and the inhibition is correlated with P_i dissociation from the F₁-ATPase catalytic site (uni-site catalysis). The F₁-ATPase-ADP complex formed under uni-site catalysis conditions can be reactivated in two ways: (i) slow ATP-dependent ADP release from the catalytic site (τ_½ 20 s) or (ii) binding of P_i in addition to MgADP and the formation of the triple F₁-ATPase-MgADP-P_i complex. GTP and GDP are also capable of binding to the catalytic site, however, without changes in the kinetic properties of the F₁-ATPase. It is proposed that ATP-dependent dissociation of the F₁-ATPase-GDP complex occurs more rapidly, than that of the F₁-ATPase-ADP complex.

【 授权许可】

Unknown