Protein hydration analysis by 17O oxygen triple-quantum-filtered relaxation

The O-17 oxygen triple-quantum-filtered relaxation was measured for water-BSA and water-lysozyme systems in different temperatures. Simultaneous analyses of transverse and longitudinal triple-quantum-filtered experiments of BSA and lysozyme solutions at different temperatures were performed. The relaxivity for the loosely bound water pool R-free, abundance of the tightly bound water pool Pb and its correlation time tau (c) were deduced from fitting the relevant functions to the experimental results, based on the simulated curves within the zeroth order perturbation calculus applied to the relaxation matrix. An alternative approach to the relaxation phenomenon using the exact solution is presented.