title: Kinetic studies on the conformational isomerization reaction of the four diastereomers of beta,gamma-bidentate CrATP.
abstract: The rates of the conformational isomerization reaction of the diastereomers of beta,gamma-bidentate CrATP were studied as a function of pH, buffer concentration, ionic strength, and temperature. The progress of the reaction was monitored by quenching the reaction at various times, and then isolating the individual diastereomers and quantitating the percent of each. This was accomplished using the reverse-phase high-performance liquid chromatography separation technique developed in this laboratory [K. J. Gruys, and S. M. Schuster, Anal. Biochem. 125, 66-73 (1982)]. The rate constants for this isomerization were then determined by obtaining the best computer fit of the data to a reversible binary mechanism (i.e., A in equilibrium B) using interative descent methods. The reaction rate was shown to be dependent on pH, temperature, and ionic strength, but independent of buffer concentration. Keq. constants were independent of all variables except ionic strength. The results from this study are interpreted in terms of a reaction mechanism involving a preequilibrium ionization of the diastereomers followed by a rate-limiting interconversion process.
mesh_terms: D000255:Adenosine Triphosphate; D002021:Buffers; D007536:Isomerism; D007700:Kinetics; D008968:Molecular Conformation
chemical_list: D002021:Buffers; D000255:Adenosine Triphosphate