Binding of [14C] DDT by submitochondrial particles.
1. Binding of [14C] DDT by submitochondrial particles and by liposomes prepared from lipids extracted from the particles was studied by the discontinuous sucrose gradient method. 2. Binding of the insecticide was a biphasic linear function of the biomembrane- and liposome-concentration with a break in the binding curve occurring at identical concentrations of phospholipid for both the biomembrane and vesicle. The biphasic binding curve is interpreted in terms of decreased availability of binding sites as a result of particle-particle interaction. 3. [14C] DDT was bound mainly by the membrane lipids and only negligible binding was detected for the delipidated membrane. 4. A 100-200-fold excess of unlabeled DDT had no effect on the binding of [14C] DDT and a 600-fold excess of unlabeled DDT reduced the binding by 20% suggesting that binding of [14C] DDT by lipids was nonspecific. 5. These results are discussed in relation to the strong inhibition by DDT of mitochondrial bioenergetics.
D000818:Animals; D002250:Carbon Radioisotopes; D003634:DDT / Q000378:metabolism*; D005260:Female; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008081:Liposomes; D051379:Mice; D008930:Mitochondria, Liver / Q000378:metabolism*; D013367:Submitochondrial Particles / Q000378:metabolism*
D002250:Carbon Radioisotopes; D008081:Liposomes; D003634:DDT