Exchange saturation transfer and associated NMR techniques for studies of protein interactions involving high-molecular-weight systems

Abstract

A brief overview of theoretical and experimental aspects of the Dark state Exchange Saturation Transfer (DEST) and lifetime line broadening ($\Delta R_{2}^{{}}$) NMR methodologies is presented from a physico-chemical perspective. We describe how the field-dependence of $\Delta R_{2}^{{}}$ can be used for determining the exchange regime on the transverse spin relaxation time-scale. Some limitations of DEST/$\Delta R_{2}^{{}}$ methodology in applications to molecular systems with intermediate molecular weights are discussed, and the means of overcoming these limitations via the use of closely related exchange NMR techniques is presented. Finally, several applications of DEST/$\Delta R_{2}^{{}}$ methodology are described from a methodological viewpoint, with an emphasis on providing examples of how kinetic and relaxation parameters of exchange can be reliably extracted from the experimental data in each particular case.