PSEUDOCONTACT SHIFTS AS CONSTRAINTS FOR ENERGY MINIMIZATION AND MOLECULAR-DYNAMICS CALCULATIONS ON SOLUTION STRUCTURES OF PARAMAGNETIC METALLOPROTEINS

The pseudocontact shifts of NMR signals, which arise from the magnetic susceptibility anisotropy of paramagnetic molecules, have been used a s structural constraints under the form of a pseudopotential in the SA NDER module of the AMBER 4.1 molecular dynamics software package, With this procedure, restrained energy minimization (REM) and restrained m olecular dynamics (RMD) calculations can be performed on structural mo dels by using pseudocontact shifts, The structure of the cyanide adduc t of the Met80Ala mutant of the yeast iso-1-cytochrome c has been used for successfully testing the calculations. For this protein, a family of structures is available, which was obtained by using NOE and pseud ocontact shifts as constraints in a distance geometry program, The str uctures obtained by REM and RMD calculations with the inclusion of pse udocontact shifts are analyzed. (C) 1997 Wiley-Liss, Inc.