Patent ID: 7904252

Claim:
A computer-implemented method of measuring a structural change in a protein when the protein is contacted with a compound, comprising the steps of: (a) selecting a domain in the protein using an input device; (b) providing information on an orientation of the domain when the protein is not in contact with the compound; (c) providing information on an orientation of the domain when the protein is in contact with the compound, by: (i) providing known atomic coordinates for the domain, (ii) providing axial variations of NMR signals, which are generated from the protein in contact with the compound in the presence of a liquid crystalline material by two-dimensional TROSY NMR spectroscopy and depend on an orientation angle of the protein and compound in a magnetic field, (iii) determining Saupe order matrix elements for the domain from the atomic coordinates for the domain and the axial variations of NMR signals using a computer processor, and (iv) diagonalizing the Saupe order matrix elements to produce information on an orientation of the domain using the processor; and (d) measuring the structural change in the protein using the processor by a difference between the information on an orientation provided in step (b) and the information on an orientation provided in step (c), wherein a structural change in the protein when the protein and the compound are contacted is digitized as degree of orientational change by: (v) providing directions of orientation tensor axes by a first three unit vectors perpendicular to each other, by using the information on an orientation of the domain in the protein before the protein is contacted with the compound, wherein the first three unit vectors are expressed by (vi) providing directions of orientation tensor axes by a second three unit vectors perpendicular to each other, by using the information on an orientation of the domain in the protein after the protein is contacted with the compound, wherein the second three unit vectors are expressed by (vii) denoting respective angles between the individual first unit vectors and the individual second unit vectors by a, b and c, and (viii) giving a degree of orientational change by the following equation: degree of orientational change= a 2 +b 2 +c 2 .