Roberton AM, Holloway CT, Knight IG, Beechey RB.A comparison
of the effects of NN'-dicyclohexylcarbodi-imide, oligomycin A
and aurovertin on enrgy-linked reactions in mitochondria and
submitochondrial particles.
Biochem J. 1968 Jul;108(3):445-56.
1. The effects of dicyclohexylcarbodi-imide, oligomycin A and aurovertin on
enzyme systems related to respiratory-chain phosphorylation were compared.
Dicyclohexylcarbodi-imide and oligomycin A have very similar functional effects,
giving 50% inhibition of ATP-utilizing and ATP-generating systems at
concentrations below 0.8nmole/mg. of submitochondrial-particle protein.
Aurovertin is a more potent inhibitor of ATP synthesis, giving 50% inhibition at
0.2nmole/mg. of protein. However, aurovertin is a less potent inhibitor of
ATP-utilizing systems: the ATP-driven energy-linked nicotinamide nucleotide
transhydrogenase is 50% inhibited at 3.0nmoles/mg. of protein and the ATP-driven
reduction of NAD(+) by succinate is 50% inhibited at 0.95nmole/mg. of protein.
2. With EDTA-particles (prepared by subjecting mitochondria to ultrasonic
radiation at pH9 in the presence of 2mm-EDTA) the maximum stimulation of the
ATP-driven partial reactions is effected by similar concentrations of oligomycin
A and dicylcohexylcarbodi-imide, but the latter is less effective. The
stimulatory effects of suboptimum concentrations of dicyclohexylcarbodi-imide
and oligomycin A are additive. Aurovertin does not stimulate these reactions or
interfere with the stimulation by the other inhibitors.
3. Dicyclohexylcarbodi-imide and oligomycin A stimulate the aerobic
energy-linked nicotinamide nucleotide transhydrogenase of EDTA-particles, but
the optimum concentration is higher than that required for the ATP-driven
partial reactions. Aurovertin has no effect on this reaction.
4. The site of action of dicyclohexylcarbodi-imide is in CF(0), the
mitochondrial fraction that confers oligomycin sensitivity on F(1) mitochondrial
adenosine triphosphatase.
PMID: 4299126
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