Dicorynomycoloyl trehalose activity: comparison of the activity of alpha,alpha'- and beta,beta'-trehalose derivatives on mitochondrial oxidative phosphorylation.

6,6'-Dicorynomycoloyl esters of alpha,alpha'- or beta;beta'-trehalose were synthesized and tested on isolated rat liver mitochondria. In contrast to the well known site-II-specific uncoupling effect of the alpha,alpha'-trehalose derivative, the beta,beta'-trehalose derivative exhibited only non-specific inhibition of active respiration in the presence of glutamate. It is proposed that this unexpected difference between the two isomers could arise from conformational differences in the carbohydrate moiety of the glycolipids, which would render the beta,beta' isomer unable to recognize targets specific to the alpha,alpha'-trehalose glycolipid.