Nuclear Magnetic Resonance Spectroscopy Applied to (Intrinsically) Disordered Proteins

Abstract

3NMR spectroscopy is undoubtedly the most suitable tool for investigating the details of IDPs. Many parameters in NMR, such as chemical shifts, line widths, spin -spin multiplet patterns, relaxation rates, and residual dipolar couplings (RDCs), are atom specifi c and harbor information about the local conformations that polypeptide chains adopt, including record of their dynamic behavior. J J J J ω J J J J J 2 2 6 4 0 3 J J

Sequence-Specific Random Coil Chemical Shifts of Intrinsically Disordered Proteins

“…In recent years, NMR spectroscopy has proven to be singular in its capacity to study intrinsically disordered proteins (IDPs) with atomic detail. − Because of the lack of a unique three-dimensional structure, the conformational state of IDPs is described by extensive ensembles derived from a thoroughgoing analysis of various experimental data. ,,− As an alternative to comprehensive structure determination, NMR chemical shifts are of significant value, since they reflect the conformational preferences of polypeptide chains with atomic resolution. − Flexible peptides and unfolded proteins display “random coil” chemical shifts, which in turn can be used as a hallmark of disorder. The deviation of a measured chemical shift from its random coil value indicates the relative tendency of the polypeptide chain to adopt either helical or extended conformations at that point in the primary sequence, thereby offering a sensitive and accurate proxy for changes in protein (dis)order and dynamics. ,− …”

Comprehensive determination of 3JHNHα for unfolded proteins using 13C′-resolved spin-echo difference spectroscopy

“…High-resolution determination of residual structure in these inherently flexible molecules is therefore necessary (Bartlett and Radford 2009 ). NMR spectroscopy is undoubtedly the most appropriate technique to offer detailed insight into disordered states, being sensitive to the length and time scales characterizing the atomic structure (Bartlett and Radford 2009 ; Eliezer 2009 ; Mulder et al 2009 ; Wirmer et al 2005 ). In our analyses of intrinsically disordered proteins (IDPs) we have been interested in the measurement of scalar coupling constants to probe the local polypeptide backbone structure.…”