Dynamical properties of fasciculin-2

Fasciculin-2 (FAS2) is a potent protein inhibitor of the hydrolytic enzyme acetylcholinesterase. A 2-ns isobaric-isothermal ensemble molecular dynamic s simulation of this toxin was performed to examine the dynamic structural properties which may play a role in this inhibition, Conformational fluctua tions of the FAS2 protein were examined by a variety of techniques to ident ify flexible residues and determine their characteristic motion. The tips o f the toxin "finger" loops and the turn connecting loops I and II were foun d to fluctuate, while the rest of the protein remained fairly rigid through out the simulation, Finally, the structural fluctuations were compared to N MR data of fluctuations on a similar timescale in a related three-finger to xin. The molecular dynamics results were in good qualitative agreement with the experimental measurements. Proteins 1999;36:447-453. (C) 1999 Wiley-Li ss, Inc.