The extent of mitochondrial F1-ATPase and adenine nucleotide carrier activity with epsilon-ATP.
1. The use of 1,N6-ethenoadenosine 5'-triphosphate (epsilon-ATP), a synthetic, fluorescent analog of ATP, by whole rat liver mitochondria and by submitochondrial particles produced via sonication has been studied. 2. Direct [3H]adenine nucleotide uptake studies with isolated mitochondria, indicate the epsilon-[3H]ATP is not transported through the inner membrane by the adenine nucleotide carrier and is therefore not utilized by the 2,4-dinitrophenol-sensitive F1-ATPase (EC 3.6.1.3) that functions in oxidative phosphorylation. However, epsilon-ATP is hydrolyzed by a Mg2+-dependent, 2,4-dinitrophenol-insensitive ATPase that is characteristic of damaged mitochondria. 3. epsilon-ATP can be utilized quite well by the exposed F1-ATPase of sonic submitochondrial particles. This epsilon-ATP hydrolysis activity is inhibited by oligomycin and stimulated by 2,4-dinitrophenol. The particle F1-ATPase displays similar Km values for both ATP and epsilon-ATP; however, the V with ATP is approximately six times greater than with epsilon-ATP. 4. Since epsilon-ATP is a capable substrate for the submitochondrial particle F1-ATPase, it is proposed that the fluorescent properties of this ATP analog might be employed to study the submitochondrial particle F1-ATPase complex, and its response to various modifiers of oxidative phosphorylation.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002458:Cell Fractionation; D004140:Dinitrophenols / Q000494:pharmacology; D004985:Ethenoadenosine Triphosphate / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism*; D009840:Oligomycins / Q000494:pharmacology; D010085:Oxidative Phosphorylation / Q000187:drug effects; D051381:Rats; D013379:Substrate Specificity
D004140:Dinitrophenols; D004985:Ethenoadenosine Triphosphate; D009840:Oligomycins; D000255:Adenosine Triphosphate; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; D000251:Adenosine Triphosphatases