Transpo of ADP in and ATP out of mitochondria is inhibited byaEUR'
atractyloside "Atractyloside inhibits oxidative phosphorylation by inhibiting the transpoer of ADP into and ATP out of the mitochondrion"- Harper ADP and Pi needs to be transpoed from the cytosol (where ATP is used for producing energy and conveed into ADP) into the mitochondrion, where ATP is resynthesized. Since the inner mitochondria] membrane is impermeable to most charged or hydrophilic substances, a transpoer is needed for the job. This transpoer is strongly inhibited by atractyloside, a plant toxin, resulting in cessation of ATP production. Inhibitors of Electron Transpo chain Inhibit complex I Inhibit Complex III Inhibit Complex IV Inhibit Complex II Rotenone- a .fish poison and an insecticide Antimycin A BAL (Dimercaprol) Cyanide Carbon monoxide Malonate - inhibits succinate dehydrogenase Amobarbital (amytal) and Hydrogen sulphide Secobarbital Sodium azide Piericidin A Inhibitors of Oxidative phosphorylation Oligomycin- oligomycin inhibits ATP synthase by blocking its proton channel, which is necessary for oxidative phosphorylation of ADP to ATP. Atractyloside- blocks the ADP-ATP transpoer Bongregate- toxin produced by pseudomonads. acts similar to atractyloside Uncouplers of Oxidative phosphorylation Uncouplers of oxidative phosphorylation in mitochondria inhibit the coupling between the electron transpo and phosphorylation reactions and thus inhibit ATP synthesis without affecting the respiratory chain and ATP synthase. Thus mitochondria uses oxygen regardless of whether ADP and Pi available or not. Uncouplers markedly increase oxygen uptake. ATPs are not being formed, rather energy is being released as heat. Thermogenin - Thermogenin (or the uncoupling protein, UCPI) is a physiological uncoupler found in brown adipose tissue that functions to generate body heat, paicularly for the newborn and during hibernation in animals 2, 4 dinitrophenol- is the most frequently used, classic uncoupler. Aspirin in high doses (other salicylates)- this explains the fever due to toxic overdoses of these drugs Dicoumarol (vitamin K analogue) CCCP (chloro carbonyl cyanide phenyl hydrazone) Calcium Valinomycin
atractyloside
oligomycin
rotenone
cyanide