Protein dynamics nuclear overhauser effect

No such chemical exchange is observed for NP2—ImH or NP3—ImH, for which WEFT-NOESY spectra have cross peaks due only to through-space nuclear Overhauser effect interactions (91). Interestingly, these two proteins have only one proline in the A-B loop (Fig. 4). However, considerable additional NMR investigation needs to be carried out in order to determine whether the chemical exchange process shown in the NOESY spectra of NPl-ImH is indeed due to the dynamics of the A-Bloop. 

Abbreviations CCK, cholecystokinin RNase. ribonuclease G-protein, guanine nucleotide binding protein GPCR, G-protein-coupled receptor. SDS sodium dodecylsulfate, CTAH. hexadecyltrimethyl ammonium hydroxide DMPC. di-myristoylphosphatidylcholine DPPC, di-palmitoylphosphatldylcholine CMC, critical micellar concentration SUV, small unilamellar vesicles CD, circular dichroism NMR, nuclear magnetic resonance hs-DC, high sensitivity differential scanning calorimetry IR-ATR, infrared attenuated total reflection spectroscopy NOE, nuclear Overhauser effect MD, molecular dynamics DMSO, dimethylsulfoxide TFE, trifluoroethanol for abbreviations of peptides see tables land 2, and fig. 11. 

Nuclear Overhauser effect (NOE) is another techiuque used to study the dynamics of water near a heterogeneous surface. NOE intensities are modulated by dipole-dipole interactions between protons of protein and water in the hydration layer. This interaction varies as where R is the separation between the two protons. Measurements of magnetization transfer using NOE have been used to obtain the residence time of the hydration water. The residence time of water molecules in the hydration layer immediate to the protein is not easily available by other techniques and is valuable information in quantifying the rigidity of the layer. 

E. T. Olejniczak, C. M. Dobson, M. Karplus, and R. M. Levy, /. Am. Chem. Soc., 106, 1923 (1984). Motional Averaging of Proton Nuclear Overhauser Effects in Proteins. Predictions from a Molecular Dynamics Simulation of Lysozyme. 

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