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Tightly bound adenosine diphosphate, which inhibits the activity of mitochondrial F 1 ‐ATPase, is located at the catalytic site of the enzyme
Author(s) -
Drobinskaya I.Ye.,
Kozlov I.A.,
Murataliev M.B.,
Vulfson E.N.
Publication year - 1985
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(85)80346-x
Subject(s) - atpase , chemistry , atp hydrolysis , atp synthase gamma subunit , nucleotide , gtp' , f atpase , adenosine diphosphate , binding site , catalysis , atp synthase , enzyme , adenosine triphosphate , dissociation (chemistry) , stereochemistry , adenine nucleotide , active site , biophysics , biochemistry , biology , platelet , thylakoid , chloroplast , platelet aggregation , immunology , gene
The binding of one ADP molecule at the catalytic site of the nucleotide depleted F 1 ‐ATPase results in a decrease in the initial rate of ATP hydrolysis. The addition of an equimolar amount of ATP to the nucleotide depleted F 1 ‐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 F 1 ‐ATPase catalytic site (uni‐site catalysis). The F 1 ‐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 F 1 ‐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 F 1 ‐ATPase. It is proposed that ATP‐dependent dissociation of the F 1 ‐ATPase‐GDP complex occurs more rapidly, than that of the F 1 ‐ATPase‐ADP complex.