Temperature dependence of anisotropic protein backbone dynamics.

摘要: The measurement of 15N NMR spin relaxation, which reports the 15N−1H vector reorientational dynamics, is a widely used experimental method to assess motion protein backbone. Here, we investigate whether motions are representative overall backbone motions, by analyzing temperature dependence and 13CO−13Cα dynamics for small proteins binase ubiquitin. latter were measured using cross-correlated relaxation experiments. data show that, on average, order parameters decrease only 2.5% between 5 30 °C. In contrast, 10% over same trajectory. This strongly indicates that there polypeptide-backbone activated at room not sensed vector. Our findings variance with common crank-shaft model predicts opposite behavior. study suggests investi...