Protein structure in anisotropic environments: Unique structural fold from orientational constraints

The mathematical foundation of the determination of protein structure from orientational constraints is described. The tools used are vector algebra, gram matrices, and determinants. The discussion begins in the general abstract setting and proceeds to a discus- sion of how the methods can be applied to the determination of protein structure using solid state nuclear magnetic resonance. Examples are given relating to the structure of the peptide gramicidin A. © 2000 John Wiley & Sons, Inc. Concepts Magn Reson 12: 71-82, 2000.