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

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 Pi 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 (τ½ 20 s) or (ii) binding of Pi in addition to MgADP and the formation of the triple F1‐ATPase‐MgADP‐Pi 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.

[1]  A. Vinogradov,et al.  Kinetic mechanism of mitochondrial adenosine triphosphatase. ADP-specific inhibition as revealed by the steady-state kinetics. , 1982, The Biochemical journal.

[2]  J. Lunardi,et al.  Studies of the nucleotide-binding sites on the mitochondrial F1-ATPase through the use of a photoactivable derivative of adenylyl imidodiphosphate. , 1982, Biochimica et biophysica acta.

[3]  B. Hess,et al.  Pre‐steady state kinetics of nucleotide‐triphosphate hydrolysis by mitochondrial F1‐ATPase from yeast , 1979, FEBS letters.

[4]  E. C. Slater,et al.  The ATP‐ and ADP‐binding sites in mitochondrial coupling factor F1 and their possible role in oxidative phosphorylation , 1979, FEBS letters.

[5]  A. E. Senior,et al.  The structure of mitochondrial ATPase. , 1973, Biochimica et biophysica acta.

[6]  H. Penefsky.  Reversible binding of Pi by beef heart mitochondrial adenosine triphosphatase. , 1977, The Journal of biological chemistry.

[7]  E. C. Slater,et al.  Tightly bound nucleotides of the energy-transducing ATPase, and their role in oxidative phosphorylation. II. The beef heart mitochondrial system. , 1977, Biochimica et biophysica acta.

[8]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[9]  R. L. Cross,et al.  Adenine nucleotide binding sites on beef heart F1-ATPase. Evidence for three exchangeable sites that are distinct from three noncatalytic sites. , 1982, The Journal of biological chemistry.

[10]  C. Grubmeyer,et al.  Mechanism of ATP hydrolysis by beef heart mitochondrial ATPase. Rate constants for elementary steps in catalysis at a single site. , 1982, The Journal of biological chemistry.

[11]  A. Vinogradov,et al.  Mg2+-induced ADP-dependent inhibition of the ATPase activity of beef heart mitochondrial coupling factor F1. , 1979, Biochemical and biophysical research communications.

[12]  E. C. Slater,et al.  Tight binding of adenine nucleotides to beef-heart mitochondrial ATPase. , 1973, Biochimica et biophysica acta.

[13]  A. Vinogradov,et al.  Kinetics of interaction of adenosine diphosphate and adenosine triphosphate with adenosine triphosphatase of bovine heart submitochondrial particles. , 1980, The Biochemical journal.

[14]  E. C. Slater,et al.  The pre-steady state and steady-state kinetics of the ATPase activity of mitochondrial F1. , 1980, Biochimica et biophysica acta.

[15]  G. Radda,et al.  Specificity of nucleotide binding and coupled reactions utilising the mitochondrial ATPase. , 1978, Biochimica et biophysica acta.

[16]  G. Lauquin,et al.  4-Azido-2-nitrophenyl phosphate, a new photoaffinity derivative of inorganic phosphate. Study of its interaction with the inorganic phosphate binding site of beef heart mitochondrial adenosine triphosphatase. , 1980, Biochemistry.

[17]  Interaction between catalytic and regulatory sites of mitochondrial F1 adenosine-5'-triphosphatase as monitored by the differential effects of inhibitors and nucleotide analogues on the "hysteretic" behavior of the enzyme. , 1981, Biochemistry.

[18]  F. Penin,et al.  "Hysteric" behavior and nucleotide binding sites of pig heart mitochondrial F1 adenosine 5'-triphosphatase. , 1980, Biochemistry.

[19]  J. Thomassen,et al.  ATPase of bovine heart mitochondria. Modulation of ITPase activity by ATP, ADP, acetyl ATP and acetyl AMP. , 1983, Biochimica et biophysica acta.

[20]  D. Harris,et al.  Studies of the kinetics of the isolated mitochondrial ATPase using dinitrophenol as a probe. , 1981, Biochimica et biophysica acta.

[21]  P. Boyer,et al.  An alternating site sequence for oxidative phosphorylation suggested by measurement of substrate binding patterns and exchange reaction inhibitions. , 1977, The Journal of biological chemistry.

[22]  J. H. Wang,et al.  Changes in chemical properties of mitochondrial adenosinetriphosphatase upon removal of tightly bound nucleotides. , 1983, Biochemistry.

[23]  D. Harris.  The interactions of coupling ATPases with nucleotides. , 1978, Biochimica et biophysica acta.

[24]  A. Knowles,et al.  The subunit structure of beef heart mitochondrial adenosine triphosphatase. Isolation procedures. , 1972, The Journal of biological chemistry.