Abstract
The chemical relaxation times of two different two-step equilibrium reactions, characterized by a 1:1 binding process followed by a subsequent rearrangement step and a stepwise 1:2 binding reaction, are analyzed for the purpose of qualitative model discrimination and quantitative determination of kinetic parameters. The equations describing the dependences of the two reciprocal relaxation times on suitable concentrations are given for both models in the general case as well as for four different limiting situations which are characterized by well separated relaxation times. The conditions corresponding to the limiting cases are expressed in terms of strong, weak and no coupling between the two partial equilibrium steps involved in both models. The coupling strength depends on the rate constants as well as on the total concentrations of the reactants. Criteria to discriminate between these two reaction models under defined limiting conditions are developed. In the general case, the product of both reciprocal relaxation times can be used to distinguish both models. If only one relaxation time can be resolved experimentally, it is possible under conditions described to determine only a reduced set of individual rate constants for most of the limiting cases considered. If both relaxation times are observed, all rate constants are determinable in the general case as well as in most of the limiting cases discussed.
Similar content being viewed by others
References
Bremer C (1992) Aufbau einer Laser-Temperatursprung-Anlage und ihre Anwendung in relaxationskinetischen Untersuchungen zur Bildung von Erdalkalikomplexen von Methylthymolblau. Dissertation, Universität, Frankfurt/M.
Bremer C, Grell E (1994) Protolysis and Mg2+ binding of methylthymol blue. Inorg Chim Acta (submitted for publication)
Czerlinsky G (1966) Chemical relaxation, Dekker; New York
Eigen M, De Maeyer L (1974) Theoretical basis of relaxation spectrometry. In: Hammes GG (ed) Techniques of Chemistry, Vol. 6, Part 2. Wiley-Interscience, New York, pp 63–146
Havsteen BH (1967) The kinetics of the two-step interaction of chymotrypsin with proflavin. J Biol Chem 242:769–771
Strehlow H, Knoche W (1977) Fundamentals of chemical relaxation. Verlag Chemie, Weinheim
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bremer, C., Grell, E. Determination of kinetic parameters from chemical relaxation data discrimination between coupled two-step binding reactions differing in stoichiometry. Eur Biophys J 23, 217–226 (1994). https://doi.org/10.1007/BF01007613
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01007613