PROTEIN SIDE-CHAIN CONFORMATIONAL-ANALYSIS OF 2-DIMENSIONAL NUCLEAR OVERHAUSER EFFECT DATA SPECTROSCOPY

A method for determining conformations of protein side chains (dihedral angle chi-1) of protein amino acid residues according to two-dimensional nuclear Overhauser effect (2D-NOE)* data is proposed. The basis for this algorithm method is in joint analysis of the dependence of proton-proton distance in the dipeptide L-amino acid units on the dihedral angles, phi, psi, and chi-1, based on local steric conditions of the polypeptide chain. Results indicate the placement of different spatial regions (phi, psi) of the amino acid residues in line with specific sets of spectral NOE parameters which clearly characterize the conformational state of their side chains in most cases. The efficiency of the method was shown by control computation with model NOE contacts as experimental data, derived from X-ray atomic coordinates of the pancreatic trypsin inhibitor molecule.