Seminar

Impact of Dynamics for the NMR analysis of Peptides in Membranes

JESUS SALGADO, PhD

Biological membranes are characterized by a high level of time and spatial disorder. However, most structural investigations of peptides in membranes are done by assuming static models for the interpretation of experimental data. Using molecular simulations, we have demonstrated recently that solid-state NMR observables can be dramatically influenced by averaging effects. In particular, the peptide orientation parameters determined from 2H-splittings or 15NCSA-(1H-15N) coupling-PISEMA, are severely affected if dynamics is ignored. We propose an alternative dynamic analysis based on the use of Gaussian distributions to describe the whole-body fluctuations of the molecule. This provides a more robust structural description which includes dynamics parameters and explains a previously unresolved paradox about the hydrophobic mismatch effect.