Planck-Benzinger Thermal Work Function: Thermodynamic Characterization of the Carboxy-Terminus of p53 Peptide Fragments

Chun,Paul W. ; Lewis, Marc S.;

The thermodynamic parameters for six p53
carboxy-terminus peptide fragments as determined by
analytical ultracentrifugal analysis were compared over the
experimental temperature range of 275–310 K to evaluate
the Gibbs free energy change as a function of temperature,
DGo(T), from 0 to 400 K using our general linear thirdorder
fitting function, DGo(T) = a ? bT2 ? cT3. Data
obtained at the typical experimental temperature range are
not sufficient to accurately describe the variations observed
in the oligomerization of these p53 fragments. It is necessary
to determine a number of thermodynamic parameters,
all of which can be precisely assessed using this general
third-order linear fitting function. These are the heat of
reaction, innate temperature-invariant enthalpy, compensatory
temperatures and the thermodynamic molecular
switch occurring at the thermal set point. This methodology
can be used to distinguish the characteristic structure and
stability of p53 carboxy-terminal fragments or other p53
mutants. It should be used for the thermodynamic characterization
of any interacting biological system.