The Auxiliary Activity family 9 (AA9) proteins are Cu2+ coordinating enzymes-which are crucial for the early stages of cellulose degradation. In this study, the force field parameters for copper-containing bonds in the Type 1 AA9 protein active site were established and used in a molecular dynamics simulation on a solvated, neutralized system containing an AA9 protein, Cu2+ and a beta-cellulose surface. The copper to cellulose interaction was evident during the dynamics, which could also be accelerated by the use of high Cu-O van der Waals parameters. The interaction of AA9, Cu2+ and cellulose is described in detail. (C) 2017 Elsevier B.V. All rights reserved.