[Action of several respiration inhibitors on the tetramethyl-p-phenyldiamine short-circuit pathway in nonphosphorylating electron transport particles in the bovine heart].

Non-phosphorylating electron transfer particles from beef heart according to CRANE et al. possess the ability to oxidize succinate via the artificial TMPD bypass of the respiratory chain. The respiratory inhibitors TTFA, carboxin, tridemorph and the inhibitory protein RF from rabbit reticulocytes act both on the normal succinate oxidase and on the bypass. The presence of antimycin A diminishes the inhibition of carboxin on the bypass, likely by way of the increase of the degree of reduction in the iron-sulphur proteins. The inhibition by an isatin-beta-isothiosemicarbazone acting on the complex III of the succinate oxidase system is relieved by TMPD analogous to antimycin A.