Characterization of pyrophosphate exchange by the reconstituted adenine nucleotide translocator from mitochondria.
The transport of inorganic pyrophosphate (PPi) by the adenine nucleotide translocator from beef heart mitochondria was studied in a reconstituted system. The transport of PPi is dependent on appropriate transmembrane substrates. The activity of PPi exchange is about one tenth as compared to the ADP/ATP exchange, whereas the transport affinity for PPi is very low (2-5 mM). The adenine nucleotide carrier catalyzes a strict counterexchange of PPi and nucleotides with an exchange stoichiometry close to 1. The inhibitor specificity of PPi exchange is comparable to that of ADP/ATP exchange.
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D011756:Diphosphates / Q000378:metabolism*; D007700:Kinetics; D008929:Mitochondria, Heart / Q000201:enzymology*; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000494:pharmacology; D013379:Substrate Specificity
D011756:Diphosphates; D010171:Palmitoyl Coenzyme A; D000255:Adenosine Triphosphate; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases