1. Angular Dependence of 3-bond J-couplings
Bax, et al. (1994) Measurement of Homo- and Heteronuclear J-couplings from
Quantitative J Correlation, Methods Enzymol., 239,

2. Detection of Hydrogen Bonds
h3JNC’ to -0.9
h2JHC’ to 1.3
h3JHCa 0.0 to 1.4
Ref: Grzesiek, et al. (2001) Methods Enzymol., 338,

3. Anisotropic Tumbling w. r. t
Anisotropic Tumbling w.r.t. to Bo Results in Residual Dipolar Couplings (RDCs)
Magnitude of the dipole-dipole interaction is orientation dependent w.r.t. to the static magnetic field (Bo)
Isotropic tumbling w.r.t. Bo normally averages dipolar couplings to zero
Small, but non-zero, magnetic susceptibility results in residual dipolar couplings that appear as apparent J-splittings

4. Induced Residual Alignment of Diamagnetic Proteins
Lipid Bicelles LC (Tjandra & Bax, Science, 1997)
Purified Bacteriophage Particles (Pf1) LC(Hansen et al, J. Am. Chem. Soc, 1998)
Deformed Pores in Nondenaturing Polyacrylamide Gel (Sass et al, J. Biomol. NMR, 2000)
dimyristoyl-phos-
phatidylcholine (DMPC)
dihexanoyl-phos-
phatidylcholine (DHPC)

5. RDC for Proteins in Solution Correlate Very Well With
Predictions from High-Resolution Crystal Structures

6. NMR Structure Determination
Start with a peptide chain of random starting conformation
Subject protein to a classical mechanical treatment (such as “simulated annealing”) that minimizes the total energy
Simulated annealing protocol is a commonly used
to minimize the energy. Protein is heated in the computer,
which allows molecular motions to occur, and then is slowly
cooled to minimize the energy (avoids local minima in the
energy landscape)