title: Hen heart AMP-deaminase--the combined effect of ATP, ADP and orthophosphate on the enzyme activity.
abstract: Interpretation of the kinetic data in terms of concerted transition theory indicated that in the presence of 100 mM potassium chloride hen heart AMP-deaminase may be active as a dimer. The presence of ATP, but not of the ADP in the incubation medium shifts completely the allosteric equilibrium towards the active, accessible to the substrate form of the enzyme. In the joint presence of main enzyme effectors (ATP, ADP and orthophosphate) added to the incubation medium at physiological concentrations, the plot of the reaction rate versus substrate concentration manifested hyperbolic dependence and the value of half-saturation constant (K0.5) did not differ from the value of this parameter obtained for ATP(alone)-activated enzyme.
mesh_terms: D000659:AMP Deaminase / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006160:Guanosine Triphosphate / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology*; D009709:Nucleotide Deaminases / Q000378:metabolism*; D010710:Phosphates / Q000494:pharmacology
chemical_list: D010710:Phosphates; D000244:Adenosine Diphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D009709:Nucleotide Deaminases; D000659:AMP Deaminase