Calculation of the partition function by integrating heat capacity curves

3 Calculation of the partition function by integrating heat capacity curves 

From equation 36 it is evident that a direct integration of a Cp(T)-curve yields the relative partition function Q [37,41,42]. Before numeric integration of the experimental Cp(T)-curve the heat capacity of the reference species has to be subtracted. For practical reasons this usually works best, if either the heat capacity of the native or that of the denatured state is used as reference heat capacity. For a reliable deconvolution of the experimental heat capacity curve it is essential that either or Cp can be extrapolated accurately into the transition region. Depending on whether the native or the denatured state is taken as reference state equation 34 shows that the following relations hold 1 Wn 1 No 

The integral can be substituted by a sum over the measured heat capacities times AT, since usually the temperature difference between two neighbouring points AT (e.g. O.IK) is sufficiently small. The temperature dependence of the fraction of native proteins is readily calculated 

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