Biochemical and biological characterization of a dermonecrotic metalloproteinase isolated from Cerastes cerastes snake venom

A dermonecrotic metalloproteinase (CcD-II) was isolated from C. cerastes venom. Venom fractionation was performed using three chromatographic steps (molecular exclusion on Sephadex G-75, ion-exchange on DEAE-Sephadex A-50, and reversed-phase high-performance liquid chromatography on C8 column). CcD-II presented an apparent molecular mass of 39.9 kDa and displayed a dermonecrotic activity with a minimal necrotic dose of 0.2 mg/kg body weight. CcD-II showed proteolytic ability on casein chains and on alpha and beta fibrinogen chains that was inhibited by ethylenediamine tetraacetic acid and 1,10-phenanthroline while remained unaffected by phenylmethylsulphonyl fluoride and heparin. CcD-II displayed gelatinase activity and degraded extracellular matrix compounds (type-IV collagen and laminin). These results correlated with histopathological analysis showing a complete disorganization of collagenous skin fibers. These data suggested that CcD-II belongs to P-II class of snake venom metalloproteinase. The characterization of venom compounds involved in tissue damage may contribute in the development of new therapeutic strategies in envenomation.