Fitting Protein NMR Titration Curves

Classically, titration curves were fitted to gain information on the pK values associated with each titration. Such titration curve fitting procedures are relatively well established, mostly consist of fitting titration curves to Eq. (2) and extensions of it, and will not be covered here. Instead 1 will focus on exfracfing additional information from protein NMR pH titration curves. 

This is further bolstered by the fact that pK calculations on large enzymes routinely produce non-HH titration curves. Indeed the THEMATICS algorithm [63] for identifying active sites in protein structures has been designed around this principle, and it has been shown that strong unfavorable electrostatic interaction energies often are present in enzyme active sites [64]. It is therefore likely fhaf a 

Since pairwise electrostatic interaction energies can be calculated from protein structures using Poisson-Boltzmann Equation (PBE) solvers [71,72], we can attempt to forge a unique link between protein structure and protein titration curves 

The NMR chemical shift does not model the titrational event If it is clear that an altered protein dielectric constant cannot reconcile the protein structure with the titration curves, then it is time to examine the NMR titration curves themselves. Since the NMR chemical shift is very sensitive to small changes in the chemical 

The unique sensitivity of the NMR chemical shift to the chemical environment is, as illustrated above (possibility no. 3), sometimes an obstacle to understanding of the titrational properties of a system. However, the high sensitivity can also be exploited to give us a information on other characteristics of a profein. 

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Describing the energy of a protonation state Fitting Protein NMR Titration Curves... 

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