IDENTIFICATION OF FUNCTIONAL AND UNFOLDING MOTIONS OF CUTINASE AS OBTAINED FROM MOLECULAR-DYNAMICS COMPUTER-SIMULATIONS

The implementation of cutinase from Fusarium solani pisi as a fat-stai n removing ingredient in laundry washing is hampered by its unfolding in the presence of anionic surfactants. In this work we present molecu lar dynamics (MD) computer simulations on cutinase and analysis proced ures to distinguish the movements related to its functional behavior ( e.g., substrate binding) from those related to the unfolding of the en zyme. Two kinds of MD-simulations were performed: a simulation mimicki ng the thermal motion at room temperature, and several simulations in which unfolding is induced either by high temperature or by using a mo dified water-protein interaction potential, Essential dynamics analyse s (A. Amadei et al., Proteins 17:412-425, 1993) on the simulations ide ntify distinct regions in the molecular structure of cutinase in which the motions occur for function and initial unfolding, The unfolding i n various simulations starts in a similar way, suggesting that mutatio ns in the regions involved might stabilize the enzyme without affectin g its functionality. (C) 1998 Wiley-Liss, Inc.