Distinguishing among Structural Ensembles of the GB1 Peptide: REMD Simulations and NMR Experiments

摘要

Detailed comparison of REMD simulations to numerous experimental NMR parameters, including HA, HN chemical shifts, J_(HAHN) scalar coupling, and NOEs has provided an approach for identifying the set of simulated ensembles that best match the low temperature experimental data. These ensembles allow the visualization of distinct populations within the confor-mational ensemble of the GB1 peptide, thereby providing access not only to averages of conformational properties, such as the number of hydrogen bonds, but also to the distributions which make up those averages. What is striking is that the ensembles that best match the experimental NMR data are very inhomogeneous and the fact that they include a large population of conformations with no native hydrogen bonds.