High-Sensitivity Detection of Nanometer 1H-19F Distances for Protein Structure Determination by 1H-Detected Fast MAS NMR.
Related Articles High-Sensitivity Detection of Nanometer 1H-19F Distances for Protein Structure Determination by 1H-Detected Fast MAS NMR.
J Phys Chem B. 2019 Apr 29;:
Authors: Shcherbakov AA, Mandala VS, Hong M
Abstract
Protein structure determination by solid-state NMR requires the measurement of many inter-atomic distances through dipole-dipole couplings. To obtain multiple long-range distance restraints rapidly and with high sensitivity, here we demonstrate a new 1H-detected fast magic-angle-spinning (MAS) NMR technique that yields many long distances in a 2D-resolved fashion. The distances are measured up to ~15 Å, with an accuracy of better than 10%, between 1H and 19F, two nuclear spins that have the highest gyromagnetic ratios. Exogenous fluorines are sparsely introduced into the aromatic residues of the protein, which is perdeuterated and back-exchanged to give amide protons. This 1H-19F distance experiment, termed 2D HSQC-REDOR, is demonstrated on the singly fluorinated model protein, GB1. We extracted 33 distances between 5-19F-Trp43 and backbone amide protons, using 2D spectral series that were measured in less than 3 days. Combining these 1H-19F distance restraints with 13C-19F distances and chemical shifts, we calculated a GB1 structure with a backbone RMSD of 1.73 Å from the high-resolution structure. This 1H-detected 1H-19F distance technique promises to provide a highly efficient tool for constraining the three-dimensional structures of proteins and protein-ligand complexes, with not only precise and fast measurements, but also access to truly long-range distances.
PMID: 31034230 [PubMed - as supplied by publisher]
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