Coenzyme A enhances activity of the mitochondrial adenine nucleotide translocator.
The adenine nucleotide translocator (ANT) accomplishes the exchange of ATP from the mitochondrial matrix with cytoplasmic ADP. While investigating the biochemical mechanism of retinoic acid (RA) on the ANT via retinoylation, we have found and subsequently demonstrated a positive influence of Coenzyme A (CoA) on the transport of ATP across the membranes of rat liver mitochondria. CoA enhances ANT activity in a dose-dependent manner modifying the V(max) (673.3+/-20.7 nmol ATP/mgprotein/min versus 155.0+/-1.9 nmol ATP/mgprotein/min), the IC(50) for the specific inhibitor carboxyatractyloside (CATR) (0.142+/-0.012 microM versus 0.198+/-0.011 microM) but not the K(m) (22.50+/-0.52 microM versus 22.19+/-0.98 microM). Data suggest a likely enzymatic involvement in the interaction between ANT and CoA. The effect of CoA is observed in mitochondria from several different tissues.
Department of Pharmaco-Biology, University of Calabria, Edificio Polifunzionale, 87036 Rende (CS), Italy.
Erika
E
Cione
Attilio
A
Pingitore
Francesco
F
Genchi
Giuseppe
G
Genchi
D033741:Adenine Nucleotide Translocator 1 / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001278:Atractyloside / Q000031:analogs & derivatives / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D003065:Coenzyme A / Q000494:pharmacology*; D015180:Electrophoresis, Gel, Two-Dimensional; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism*; D008958:Models, Molecular; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D033741:Adenine Nucleotide Translocator 1; D001278:Atractyloside; D003065:Coenzyme A; C003853:carboxyatractyloside