Solid-state nuclear magnetic resonance investigation of protein and polypeptide structure

Solid-state nuclear magnetic resonance (NMR) is rapidly emerging as a succe ssful and important technique for protein and peptide structural elucidatio n from samples in anisotropic environments. Because of the diversity of nuc lei and nuclear spin interactions that can be observed, and because of the broad range of sample conditions that can be studied by solid-state NMR, th e potential for gaining structural constraints is great. Structural constra ints in the form of orientational, distance, and torsional constraints can be obtained on proteins in crystalline, liquid-crystalline, or amorphous pr eparations. Great progress in the past few years has been made in developin g techniques for obtaining these constraints, and now it has also been clea rly demonstrated that these constraints can be assembled into uniquely defi ned three-dimensional structures at high resolution. Although much progress toward the development of solid-state NMR as a routine structural tool has been documented, the future is even brighter with the continued developmen t of the experiments, of NMR hardware, and of the molecular biological meth ods for the preparation of labeled samples.