The results presented in this paper show that accurate through-space internuclear distance measurements can be performed on doubly labeled retinals using the one-dimensional approach to the solid... Show moreThe results presented in this paper show that accurate through-space internuclear distance measurements can be performed on doubly labeled retinals using the one-dimensional approach to the solid state magic angle spinning (MAS) rotational resonance NMR technique. The apparent splitting Delta omega(1) of the resonances at n = 1 rotational resonance for the labeled vinylic positions of (all-E)-[10,20-C-13(2)]retinal, (all-E)-[11,20-C-13(2)]retinal, and (all-E)-[12,20-C-13(2)]retinal can be simulated with a coherent set of parameters. From a series of simulations with different dipolar coupling constant brs, it appears that b(IS)/2 pi root 8 = 1.15(Delta omega(1)/2 pi) + 7 (Hz) to a good approximation. Using this relationship as a calibration, it is demonstrated with a set of model compounds that straightforward Lorentzian fitting to measure Delta omega(1) can be used to determine internuclear distances up to 0.44 nm in doubly labeled retinals in the solid state. Show less
