Basic Kirkwood – Buff Theory of Solution Structure and Appropriate Application of Wyman Linkage Equation to Biochemical Phenomena

Background: Researchers who have shown interest in the consequence of introducing dry biomolecules or a solution of it into cosolvents generally known as osmolyte, have applied many models for the elucidation of the scientific basis of the results obtained. The Kirkwood and Buff theory (KBT) or its reverse form has been the basis for the interpretation of the effect of the osmolyte. There seems to be no generally acceptable definition of terms in the basic KBT mathematical formalism. There is also error in stated equations describing solution structure and misapplication of Wyman linkage relation. Therefore, the objectives of this research are 1) to show how the equation of preferential interaction parameter is derived based on KBT, 2) to show the appropriate way in which Wyman linkage relation can be applied, 3) to apply biochemical approach (using generated data) to the equation of preferential interaction parameter (preferential interaction parameter is symbolised as ) for its calculation and calculation of parameters linked to KBT derived equations.

Methods: The research is mainly theoretical and partly experimental. The experiment entails Bernfeld method of enzyme assay for the generation of data.

Results and Discussion: The change in solvation preference upon the ethanol partial denaturation of the enzyme and the corresponding change in preferential interaction parameter were respectively positive and negative in sign. Unexpectedly ethanol was preferentially excluded from the enzyme.

Conclusion: The equations of preferential interaction parameters were derived. The appropriate way is either by calculation or measurement of preferential interaction parameter. Therefore, or for the change, cannot be a constant (or slope) and an instrumentation–based measurable parameter at the same time. Based on Wyman linkage relation, purely biochemical thermodynamic parameter is linked to preferential interaction parameters which are therefore, thermodynamic parameters.