The mechanism of action of uncouplers of oxidative phosphorylation
involves:
a) Inhibition of ATP synthase
b) Stimulation of ATP synthase
c) Disruption of proton gradient across the inner membrane
d) Disruption of proton gradient across outer membrane
Correct Answer - C
Uncouplers are protein carriers that can freely pass through the inner mitochondrial
membrane.
It allows translocation of the protons into the intermembranous space during the electron
transport in the respiratory chain but blocks the formation of proton gradient across the
inner mitochondrial membrane.
Thermogenin a protein present in the inner mitochondrial membrane of adipocytes is
an example of physiologic uncouplers of oxidative phosphorylation.
Examples of uncouplers are: 2,4 dinitrophenol, pentachlorophenol, nigericin,
thyroxin and thermogenin.
Ref: Jaypee’s Review of Med. Biochemistry By S. M. Raju page 102