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NMR “Crystallography” for Uniformly ( 13 C, 15 N)‐Labeled Oriented Membrane Proteins
Author(s) -
Awosanya Emmanuel O.,
Lapin Joel,
Nevzorov Alexander A.
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201915110
Subject(s) - crystallography , model lipid bilayer , chemistry , solid state nuclear magnetic resonance , dipole , transmembrane protein , membrane protein , biomolecular structure , chemical shift , peptide , nuclear magnetic resonance spectroscopy , membrane , protein structure , nuclear magnetic resonance , topology (electrical circuits) , physics , lipid bilayer , stereochemistry , mathematics , biochemistry , receptor , organic chemistry , combinatorics , lipid bilayer phase behavior
In oriented‐sample (OS) solid‐state NMR of membrane proteins, the angular‐dependent dipolar couplings and chemical shifts provide a direct input for structure calculations. However, so far only 1 H– 15 N dipolar couplings and 15 N chemical shifts have been routinely assessed in oriented 15 N‐labeled samples. The main obstacle for extending this technique to membrane proteins of arbitrary topology has remained in the lack of additional experimental restraints. We have developed a new experimental triple‐resonance NMR technique, which was applied to uniformly doubly ( 15 N, 13 C)‐labeled Pf1 coat protein in magnetically aligned DMPC/DHPC bicelles. The previously inaccessible 1 H α – 13 C α dipolar couplings have been measured, which make it possible to determine the torsion angles between the peptide planes without assuming α‐helical structure a priori. The fitting of three angular restraints per peptide plane and filtering by Rosetta scoring functions has yielded a consensus α‐helical transmembrane structure for Pf1 protein.