Conformational creatine

Five conformationally restricted analogs of creatine now have been prepared. These are D-N-amidinoproUne, 19 LN-amidinoproline, 20 l-carboxymethyl-2-iminoimidazolidine, 21 l-carboxymethyl-2-iminohexa-hydropyrimidine, 22 and D,L3-methyl-4-carboxy-2-iminoimidazolidine (the L enantiomer is depicted in structure 23). 

Rao, B. D. N. Two-dimensional transferred nuclear Overhauser effect spectroscopy (TRNOESY) smdies of nucleotide conformations in creatine kinase complexes effects due to weak nonspedftc binding. Biochemistry 1993,... 

Wang S, Wang X, Shi W et al (2008) Detection of local polarity and conformational changes at the active site of rabbit muscle creatine kinase with a new arginine-specific fluorescent probe. Biochim Biophys Acta 1784 415 -22... 

CNDO/2 Theoretical calculations have been used to predict the favoured conformations of creatine and creatine derivatives, including phosphocreatine. These calculations predict that phosphocreatine may adopt conformation (35) to avoid unnecessary steric and electrostatic repulsions.110 The possibility also exists that creatine kinase phosphorylates creatine stereospecifically to form the favoured conformation (35) at the active site of the enzyme. When chicks are fed a diet containing cyclocreatine (l-carboxymethyl-2-iminoimidazole), the phosphorylated... 

ATP Triphosphate Chain Conformation. Much of the work in the area of ATP triphosphate chain conformation has been performed by Cleland and co-workers (14--16). Their studies on metal(III)ATP interactions with kinases have led to the classification of kinases according to the stereochemistry of the polyphosphate chain as it binds to the active site. For the kinases they studied (hexokinase, glycerokinase, creatine kinase, phosphofructokinase, 3-phosphoglycerate kinase, acetate kinase, arginine kinase, adenylate kinase and pyruvate kinase) it was found that B, y-bidentate chromi M(III)-ATP (CrATP) and not a,6,y-tridentate CrATP is a... 

Fig. 5. A schematic view of the substrates in the transition state of the reaction catalyzed by creatine kinase. Coordination of Mn(II) to the pro-S oxygen at P is established by EPR the conformation of creatine is based on the efficacy as substrates of conformationally restricted analogs of creatine. The /3,y-chelate ring of ATP is in the A configuration (76).

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