title: The alpha beta-methylene analogues of ADP and ATP act as substrates for creatine kinase. delta G0 for this reaction and for the hydrolysis of the alpha beta-methylene analogue of ATP.
abstract: The alpha beta-methylene analogues of ATP and ADP, [alpha beta CH2]ATP and [alpha beta CH2]ADP, are substrates for creatine kinase. However, the rate of the phosphoryl transfer reaction catalysed is about 10(-5)-times lower than that with normal ATP. The affinities of the analogues (especially [alpha beta CH2]ADP) for the enzyme are lower than those of the normal substrates. The equilibrium constant at 25 degrees C, measured using 31P NMR, for the reaction Mg[alpha beta CH2]ATP + creatine in equilibrium Mg[alpha beta CH2]ADP + phosphocreatine + H+ is 2.2 X 10(-12) M compared with a value of 2.5 X 10(-10) M for the same reaction with the normal substrates, corresponding to a difference in delta G0 values of 11.7 kJ X mol-1. It follows that delta G0 for the hydrolysis of the terminal phosphate group of Mg[alpha beta CH2]ATP is less favourable by 11.7 kJ X mol-1 than that for MgATP.
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D003402:Creatine Kinase / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D013379:Substrate Specificity
chemical_list: C523965:alpha,beta-methyleneadenosine 5'-diphosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003402:Creatine Kinase; C002630:alpha,beta-methyleneadenosine 5'-triphosphate