Isotopic exchange probed through NMR spectroscopy has been a precious source of information regarding local protein unfolding processes due to its ability to observe the exchange rate of single residues' amide sites. BLUU-Tramp extends this information allowing to follow, through two series of experiments, how the exchange constants vary over temperature.
In this thesis a novel approach is introduced by means of an ad hoc calculation routine which is able to extract thermodynamic parameters from the decays of the amide signals, obtained through suitable treatment of the experimental data by another original routine (TinT) of the suite devised in our laboratory. By assuming that the isotopic exchange rates can be approximated with the EX2 limit, it is possible to estimate both the ΔG of local unfolding and other underlying thermodynamic parameters, in particular the ΔCp.
The method is used to obtain these parameters in two human proteins, β2-microglobulin and lysozyme.
Furthermore, a similar computational approach is presented which is able to extract thermodynamic parameters from classical isotopic exchange experiments carried out at various different temperatures. Comparisons among the results extracted from BLUU-Tramp series and classical exchange experiments are drawn and critical aspects in the latter kind of experiments are discussed
