Synthesis and properties of fluorescent derivatives of atractyloside as potential probes of the mitochondrial ADP/ATP carrier protein

The chemical synthesis of fluorescent derivatives of atractyloside (ATR), an inhibitor of the mitochondrial ADP/ATP carrier protein, is described. These derivatives are the following: 6′-O-dansyl ATR, 6′-O-dansyl-aminobutyryl ATR, and 6′-O-naphthoyl ATR. The spectral properties of these analogs were analyzed, and their biological features were compared to those of ATR. The fluorescence emission of the dansyl ATR derivatives was increased in organic solvents and that of naphthoyl ATR was decreased; for both analogs, solubilization in organic solvents resulted in a blue shift of the emission peak. The fluorescent dansyl and naphthoyl ATR derivatives were specifically recognized by the mitochondrial ADP/ATP carrier protein. Because of their spectral properties and their biochemical reactivities, the fluorescent analogs of ATR can be considered as potential probes to investigate the topography of the ADP/ATP carrier in the mitochondrial membrane and to monitor conformational changes of the ADP/ATP carrier protein associated with transport.