Cooperativity calculation from protein structure

The value of 2(- 8gt can be calculated from standard values8 and a from the structure of the protein. A low value of mD N, compared with that calculated, indicates that the protein does not become highly unfolded on denaturation. The value of mD N thus provides a test for the degree of unfolding. A low value of mD N may also indicate that the denaturation process is occurring stepwise rather than in a single cooperative transition. 

On the other hand, the ratio obtained for pancreatic trypsin inhibitor calculated per mole of monomer unit is near 0.5, suggesting that the cooperative unit of this protein is a dimer. Thus, we see that it is not possible to generalize completely about the size of a cooperative unit from a knowledge of the protein structure, but that the comparison of these two enthalpy measurements provides insights into the presence of discrete units within the protein domain. 

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