Estimation of CH Bond Lengths Using 2Q Filtered 13C NMR,
Solid State NMR is one of the few methods capable of extracting accurate molecular structure information from large non-crystallized molecules, such as membrane proteins. Rhodopsin is the molecular photoreceptor responsible for the primary visual response through retinal, the visual chromophore, in vertebrate rode cell. In preparation for solid-state NMR studies of rhodopsin and its photointermediate, we performed 2Q filtered 13C NMR on the model compound, all-E-[11,12-13C2]-retinal to estimate the CH bond lengths of H-C11 and H-C12. The results are also compared with some other methods. The CH bond lengths will be useful for analyzing the results of MQ torsional angle determinations on rhodopsin and its photointermediate.