Molecular Dynamics Modellization and Simulation of Water Diffusion through Plant Cutin

A theoretical molecular modelling study has been conducted for cutin, the biopolyester that forms the main structural component of the plant cuticle. M olecular dynamics (M D ) simulations, extended over several ten picoseconds, suggests that cutin is a moderately flexi­ ble netting with motional constraints mainly located at the cross-link sites of functional ester groups. This study also gives structural information essentially in accordance with previously reported experimental data, obtained from X-ray diffraction and nuclear magnetic resonance experiments. M D calculations were also performed to simulate the diffusion of water m ole­ cules through the cutin biopolymer. The theoretical analysis gives evidence that water perm e­ ation proceedes by a “hopping mechanism”. Coefficients for the diffusion of the water m ole­ cules in cutin were obtained from their mean-square displacements yielding values in good agreement with experimental data.