Investigations of kinase substrate specificity with aqua Rh(III) complexes of adenosine 5'-triphosphate.
In this paper the substrate activities and binding affinities of the stereoisomers of the beta,gamma-bidentate Rh(H2O)4ATP and alpha,beta, gamma-tridentate Rh(H2O)3ATP complexes toward selected members of the kinase family of enzymes are reported. Hexokinase and glycerokinase were found to be specific for the delta beta, gamma-bidentate Rh(H2O)4ATP isomer as substrate while adenylate kinase was found to specifically catalyze the reaction of the delta beta,gamma-bidentate Rh(H2O)4ATP isomer. Pyruvate kinase recognized both the delta beta,gamma-bidentate Rh(H2O)4ATP isomer and the delta beta-P, exo alpha-P alpha,beta,gamma-tridentate Rh(H2O)3ATP isomer as substrates in the catalyzed phosphorylation of the alternate substrate, glycolate. 31P NMR analysis of the respective product complexes showed that alpha-P phosphoryl ligand exchange had not preceded or followed catalysis. Creatine kinase was found to be specific for the delta beta-P, exo alpha-P alpha,beta,gamma-tridentate Rh(H2O)3ATP isomer. Discrimination of the Rh(H2O)nATP isomers via preferential binding of the substrate-active isomer was observed for hexokinase and adenylate kinase but not for glycerokinase, fructose-6 phosphate kinase, creatine kinase, arginine kinase, or acetate kinase.
Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
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Dunaway-Mariano
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D003035:Cobalt / Q000737:chemistry; D003402:Creatine Kinase / Q000378:metabolism; D005991:Glycerol Kinase / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D007536:Isomerism; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000378:metabolism*; D010770:Phosphotransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000378:metabolism; D013379:Substrate Specificity
D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; C080110:bidentate tetraaquarhodium adenosine 5'-triphosphate complex; C080111:tridentate triaquarhodium-adenosine 5'-triphosphate complex; D003035:Cobalt; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D006593:Hexokinase; D005991:Glycerol Kinase; D011770:Pyruvate Kinase; D003402:Creatine Kinase