Evidence for Penetration in Liposomes and in Mitochondrial Membranes of a Fluorescent Analogue of Cord Factor

Abstract

A fluorescent analogue of cord factor, a glycolipid toxin of mycobacteria, has been synthesized and its interactions with liposomes and isolated mitochondria have been studied. This compound, methyl α‐D‐6[12‐(9‐anthroyl)stearoyl]glucoside, is shown to be active against oxidative phosphorylation. When spread as a monolayer at the air‐water interface, it forms a well organized phase and it strongly interacts with phosphatidylcholine. Addition of phosphatidylcholine liposomes or of isolated mitochondria to a water dispersion of this fluorescent cord factor analogue results in a large increase of the fluorescence intensity. Moreover, the glycolipid probes for the temperature‐dependent phase transition of the added suspensions. It is thus suggested that this cord factor analogue penetrates within mitochondrial membranes, a result which is discussed with respect to our previous conclusions concerning the way natural cord factors can interact with these organelles. Copyright © 1980, Wiley Blackwell. All rights reserved