Abstract
1. 1. The ADP-ATP and P i-ATP exchange reactions have been studied in rat-liver mitochondria under conditions in which both exchanges are completely sensitive to oligomycin. Endogenous respiration was inhibited by cyanide. 2. 2. Phosphate stimulates the ADP-ATP exchange. 3. 3. ADP inhibits the P i-ATP exchange and, above 0.5 mM, the ADP-ATP exchange. At ADP concentrations lower than 0.5 mM, the rate of the ADP-ATP exchange is lower than that of the P i-ATP exchange. At higher concentrations, the rates are equal. Under these conditions, the rate of both exchange reactions is probably limited by the rate of entry of ATP via the adenine nucleotide translocator. 4. 4. Both exchange reactions are inhibited by succinate, β-hydroxybutyrate or malonate. Inhibition by malonate is competitive with ATP. Thus, inhibition by substrate is not due to reduction of the respiratory chain but to competition between the substrate anion and ATP for entry into the mitochondrion.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
