title: [Allosteric modification of adenylate deaminase activity: appearance of adenosine deaminase activity as an effect of potassium ions].
abstract: The activation of purified adenylate deaminase from the duck myocardium by K+ is accompanied by modification of the substrate specificity and by the appearance of the capacity to deaminate adenosine and adenine. Adenosine deaminase activity originates at the concentration of K+ of 0.15 M that possesses the most stimulating effect on adenylate deaminase activity; with the increase of potassium ions concentration adenosine deaminating activity is enhanced as well, with a parallel reduction of Hill's constant. The PH-dependence, mode of inhibition by phosphate ions and the effect of alkaline metals suggests that adenosine deamination is carried out by natural adenylate deaminase active centres when their conformation is changed under the activator action.
mesh_terms: D000659:AMP Deaminase; D000243:Adenosine Deaminase; D000495:Allosteric Site; D055598:Chemical Phenomena; D002621:Chemistry; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009700:Nucleoside Deaminases; D009709:Nucleotide Deaminases; D010710:Phosphates; D011188:Potassium; D013379:Substrate Specificity
chemical_list: D010710:Phosphates; D009700:Nucleoside Deaminases; D009709:Nucleotide Deaminases; D000243:Adenosine Deaminase; D000659:AMP Deaminase; D011188:Potassium
vernacular_title: Allostericheskaia modifikatsiia aktivnosti adenilatdezaminazy: vozniknovenie adenozindezaminaznoĭ aktivnosti pod deĭstviem ionov kaliia.