Gause EM, Buck MA, Douglas MG.Binding of citreoviridin to
the beta subunit of the yeast F1-ATPase.
J Biol Chem. 1981 Jan 25;256(2):557-9.
Citreoviridin, a nonfluorescent inhibitor of bovine and
bacterial ATPases, also inhibits the yeast F1 (K1 = 2 microM).
The beta subunit-specific fluorescent ligand, aurovertin, has
been used to report the interaction of citreoviridin with the
yeast F1-ATPase and the isolated beta subunit. Citreoviridin
caused a marked decrease in the fluorescence increment
associated with the binding of aurovertin to either intact F1 or
the isolated beta subunit. Three lines of evidence indicate that
citreoviridin and aurovertin bind to nonidentical sites on the
beta subunit:
- the binding of citreoviridin to the F1 or isolated beta
subunit is noncompetitive with respect to aurovertin;
- the number of aurovertin binding sites (Kd = 0.2 to 0.6
microM) per F1-ATPase molecule remains the same (1.89 +/-
0.6 mol of aurovertin bound per mol of F1) in the presence
or absence of citreoviridin;
- the F1-ATPase obtained from the aurovertin-resistant
mutant aur-1 is partly inhibited by citreoviridin.
PMID: 6450205 |
