Molecular dynamics simulations on the mycotoxin fumonisin B-1

The solution conformational properties of the mycotoxin fumonisin B-1 have been studied using molecular dynamics methodology Fumonisins have been show n to inhibit sphinganine (sphingosine) N-acyltransferase (ceramide synthase ) and show a wide range of toxic effects in many animals. This study of the solution properties of fumonisin B-1 attempts to add to the structural mod els necessary for the understanding of the binding and activity properties. The computational method uses a box with periodic boundaries, filled with explicit TIP3P water molecules, the substrate fumonisin B-1, and selected c ounterions for charge neutrality. The starting structure of fumonisin B-1 i s added to the box by excluding water molecules. The explicit image method using 12-Angstrom cutoffs is applied to the system and molecular dynamics a re carried out on different starting conformations at 300 K in 100-picoseco nd (ps) steps. Examination of the resulting equilibrated conformations sugg ests that the structure is relatively extended and that previous computatio nal studies in vacuo, showing a compact folded structure, may not be consis tent with the solution structure.