STRUCTURE AND INTERNAL DYNAMICS OF THE BOVINE PANCREATIC TRYPSIN-INHIBITOR IN AQUEOUS-SOLUTION FROM LONG-TIME MOLECULAR-DYNAMICS SIMULATIONS

Structural and dynamic properties of bovine pancreatic trypsin inhibit or (BPTI) in aqueous solution are investigated using two molecular dyn amics (MD) simulations: one of 1.4 ns length and one of 0.8 ns length in which atom-atom distance bounds derived from NMR spectroscopy are i ncluded in the potential energy function to make the trajectory satisf y these experimental data more closely. The simulated properties of BP TI are compared with crystal and solution structures of BPTI, and foun d to be in agreement with the available experimental data, The best ag reement with experiment was obtained when atom-atom distance restraint s were applied in a time-averaged manner in the simulation, The polype ptide segments found to be most flexible in the MD simulations coincid e closely with those showing differences between the crystal and solut ion structures of BPTI. (C) 1995 Wiley-Liss, Inc.