the use of matrix metalloproteinases , mutated and not mutated , for the preparation of pharmaceutical compositions useful in the treatment of pathologies associated with an accumulation of matrix bio - polymers and / or an excess of timps is described ; mutated matrix metalloproteinases , in which at least an aminoacid residue in a definite position in the protein , has been mutated into a hydrophilic and / or charged aminoacidic residue , obtaining an increased stability toward autoproteolysis are also described .