Persistent Protein Motions in a Rugged Energy Landscape Revealed by Normal Mode Ensemble Analysis

Testing the premise of evolutionarily optimized protein dynamics has remained an experimental challenge. Most measurements fail to isolate specific structural motions. Our simulations show that the structural variation of a single protein in time results in variation in the vibrations leading to the observed broad and featureless optical absorption. However, when the thermal population of a protein’s configurations are considered, vibrations with functional displacements are concentrated in specific frequency bands. These emergent dynamics are apparent in anisotropic optical absorbance, indicating an experimental avenue for measuring these motions and their impact on biological function.