NMR Chemical Exchange in Mapping the Protein-Ligand Binding Site

Chemical exchange is one of the most extensively studied phenomenon in NMR spectroscopy to identify and establish the mechanism of interaction between molecules of interest (protein-ligand). While the exchange regimes are classified into three types based on the experimentally observed spectral pattern, the theory underlying all these three regimes is general. In order to delineate the mechanism of interaction through chemical exchange, mechanism dependent ligand correction and evaluation of population are necessary. For a simple system the data analysis is easier compared to the complex systems, where both the ligand correction and parameter optimization are to be performed simultaneously. This analytical difficulty has been overcome by adopting a genetic algorithm based approach for data analysis using numerical method. The computational implementation is available in the form of open source C programs: 'Auto-FACE' for fast chemical exchange and 'AUTOMEX' for all exchange regimes.