On Mon, 2 Mar 1998, Dr E. Buxbaum wrote:
> Louis Hom wrote:
> > Basic question:
> > Is there an activation energy associated with ligand binding?
>> Yes, there is, and it is easy to measure. Simply determine the Kd at
> various temperatures and plot ln(Kd) vs the reciprocal temperature
> (absolute temperature, i.e. in Kelvin). If certain conditions are met,
> then the data points will be on a straight line, from the slope of which
> you can calculate the activation energy.
>>There seems to be some confusion about kinetic and equilibrium processes.
Kinetic processes yield the activation energy when the ln(rate constant)
if plotted vs i/T. Equilibrium processes yield the standard enthalpy
change when the equilibrium/dissociation constant is substituted for the
rate constant in the ln term.
Janice S. Barton, Ph.D.
Professor and Chair of Chemistry
Department of Chemistry
Washburn University, Topeka, KS 66621
zzbart at washburn.edu