Temperature Effects on Binding Equilibrium and Reaction Rate

Abstract

This type of investigation is quite important for the characterisation of an enzyme:

$$\Delta {G'}^{0} = -R {_\ast} T {_\ast}\ln (1/{K}_{\mathrm{ d}})\qquad \mathrm{at}\,\,25\mathrm{\!\circ \mathrm{C}}$$

(44.1)

$$\ln ({K}_{\mathrm{d}}) = -\dfrac{\Delta {H'}^{0}} {R} {_\ast} \dfrac{1} {T} + A$$

(44.2)

$$\Delta {S'}^{0} = \dfrac{\Delta {H'}^{0} - \Delta {G'}^{0}} {T}$$

(44.3)

Such experiments can be performed on a Forbes-bar (see Fig. 44.1), that allows measurements at different temperatures in parallel. The standard Gibbs free energy of ligand binding¹ Δ G ′ ⁰ can be determined from the dissociation constant at standard temperature (25∘C)