title: NH-NH vector correlation in peptides by solid-state NMR.
abstract: We present a novel solid-state magic angle-spinning NMR method for measuring the NH(i)-NH(i+1) projection angle &theta;(i,i+1) in peptides. The experiment is applicable to uniformly (15)N-labeled peptides and is demonstrated on the chemotactic tripeptide N-formyl-l-Met-l-Leu-l-Phe. The projection angle &theta;(i,i+1) is directly related to the peptide backbone torsion angles &phi;(i) and psi(i). The method utilizes the T-MREV recoupling scheme to restore (15)N-(1)H interactions, and proton-mediated spin diffusion to establish (15)N-(15)N correlations. T-MREV has recently been shown to increase the dynamic range of the (15)N-(1)H recoupling by gamma-encoding, and permits an accurate determination of the recoupled NH dipolar interaction. The results are interpreted in a quasi-analytical fashion that permits efficient extraction of the structural parameters.
authors.affiliation: Department of Chemistry and MIT/Harvard Center for Magnetic Resonance, Cambridge, Massachusetts, 02139, USA.
authors.forename: B
authors.initials: B
authors.lastname: Reif
authors.forename: M
authors.initials: M
authors.lastname: Hohwy
authors.forename: C P
authors.initials: CP
authors.lastname: Jaroniec
authors.forename: C M
authors.initials: CM
authors.lastname: Rienstra
authors.forename: R G
authors.initials: RG
authors.lastname: Griffin
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000737:chemistry*; D009587:Nitrogen Isotopes; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D009587:Nitrogen Isotopes; D009842:Oligopeptides; D009240:N-Formylmethionine Leucyl-Phenylalanine