Measurement of Long-Range Interatomic Distances by Solid-State Tritium-NMR Spectroscopy

摘要

Solid-state NMR has clearly proven to be valuable for probing molecular structure, owing to its ability to measure accurate interatomic distances. In the absence of high-resolution X-ray data, such measurements are mandatory for determining the conformation of a small molecule bound to an insoluble or membrane protein. Knowledge of this conformation is of key importance in drug design. Long-range distances can be determined using either beacons such as ~(19)F (distances up to 8 A) or paramagnetic spin labels (up to 20 A). In both of these cases, however, modification of the ligand structure is an unwanted consequence. Isotopic labeling using ~(13)C-~(13)C or ~(13)C-~(15)N does not lead to structural modifications, but only short distances can be measured (5-6 A).