Determination of backbone angle psi in proteins using a TROSY-based alpha/beta-HN(CO)CA-J experiment.
Transverse relaxation-optimized NMR experiment (TROSY) for the measurement of three-bond scalar coupling constant between (1)H(alpha)(i-1) and (15)N(i) defining the dihedral angle psi is described. The triple-spin-state-selective experiment allows measurement of (3)J(H(alpha)N) from (13)C(alpha), (15)N, and (1)H(N) correlation spectra H(2)O with minimum resonance overlap. Transverse relaxation of (13)C(alpha) spin is minimized by using spin-state-selective filtering and by acquiring a signal longer in (15)N-dimension in a manner of semi-constant-time TROSY evolution. The (3)J(H(alpha))(N) values obtained with the proposed alpha/beta-HN(CO)CA-J TROSY scheme are in good agreement with the values measured earlier from ubiquitin in D(2)O using the HCACO[N] experiment.
Permi
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Institute of Biotechnology, University of Helsinki, 00014, Finland. Perttu.Permi@helsinki.fi
Kilpeläinen
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Annila
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D000465:Algorithms; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D014452:Ubiquitins / Q000737:chemistry
D011506:Proteins; D014452:Ubiquitins