Current understanding on the collagenolytic activity performed by the MMPs assumes some degree of relative motion between the catalytic and the hemopexin-like domains of the enzyme. However, all the crystal structures available for the full-length enzymes display a compact arrangement of the protein domains. Herein, we employ Molecular Dynamics simulations to investigate the structure of the full-length MMP-2 enzyme in aqueous solution. This simulation, together with previous experimental results that have been obtained very recently for the MMP-9 and MMP-12 enzymes, gives strong support to the hypothesis that the interdomain dynamics of the MMP enzymes in solution can result in a manifold of conformations including some structures with a large interdomain separation. The simulation of MMP-2 provides also a detailed molecular picture of the structures involved in the transition from the compact X-ray arrangement to the extended form in solution. Such information could be helpful in future studies of the regulation and/or the collagenolytic activity of these