[Reaction mechanism of succinyl CoA synthetase from pigeon thoracic muscle].
The ability of succinyl-CoA-synthetase from pigeon thoracic muscle to interact with ATP is investigated. gamma-32P-ATP and 8-14C-ATP were used in experiments. It is found that the enzyme, when reacting with ATP in the presence of Mg2+, forms a complex containing 2 moles of ATP residue and 2 moles of phosphoric acid residue (splitted from ATP) per 1 mole of protein. After 2 hours of incubation at 0-4 degrees C, the complex is converted into another one, containing 4 residues of phosphoric acid per 1 mole of @protein. Both complexes are active, and their incubation with succinate and CoA results in the formation of succinyl-CoA. The reaction capacity of these enzyme complexes with some reaction substrates is investigated. The enzyme complex containing 2 phosphoric acid residues and 2 nucleotide residues is found to interact neither with CoA, nor with succinate. The enzyme complex containing 4 phosphoric acid residues does not react with CoA, but it interacts with 14C-succinate, releasing inorganic phosphate in the amount equivalent to the equimolar amount of protein-binding succinic acid.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003066:Coenzyme A Ligases / Q000378:metabolism*; D003080:Cold Temperature; D010856:Columbidae / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000378:metabolism; D009132:Muscles / Q000201:enzymology*; D011485:Protein Binding; D013389:Succinate-CoA Ligases / Q000378:metabolism*; D013909:Thorax
D009097:Multienzyme Complexes; D000255:Adenosine Triphosphate; D003066:Coenzyme A Ligases; D013389:Succinate-CoA Ligases; D008274:Magnesium
Izuchenie mekhanizma reaktsii suktsinil-CoA-sintetazy grudnoí myshtsy golubia.