Long-range 1H-19F distance measurement in peptides by solid-state NMR.
A new NMR technique for determining long-range 1H-19F distances in solids is demonstrated. Using a modified rotational-echo double resonance (REDOR) sequence involving 1H homonuclear decoupling and composite 19F pulses, we show that it is possible to determine 1H-19F distances to approximately 8 A. The detrimental effect of the large 19F chemical shift to REDOR dephasing is partially compensated for by the composite pulse, 90 degrees 225 degrees 315 degrees . The 1HNLeu-19FPhe distance in the peptide f-MLF-OH was found to be 7.7 A. This was used to refine the Phe side chain conformation. The 1H-19F REDOR technique should be useful for restraining the three-dimensional structure of proteins.
Department of Chemistry, Iowa State University, Gilman 0108, Ames, IA 50011, USA.
Sungsool
S
Wi
Neeraj
N
Sinha
Mei
M
Hong
D016880:Anisotropy; D002630:Chemotactic Factors / Q000737:chemistry; D004151:Dipeptides / Q000737:chemistry*; D005461:Fluorine; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D011522:Protons
D002630:Chemotactic Factors; D004151:Dipeptides; D010455:Peptides; D011522:Protons; C017330:N-formylmethionylphenylalanine; D005461:Fluorine