CcMP-II, a new hemorrhagic metalloproteinase from Cerastes cerastes snake venom: Purification, biochemical characterization and amino acid sequence analysis

Snake venom metalloproteinases (SVMPs) are the most abundant components in snake venoms. They are important in the induction of systemic alterations and local tissue damage after envenomation. CcMP-II, which is a metalloproteinase purified from Cerastes cerastes snake venom, was obtained by a combination of gel filtration, ion-exchange and affinity chromatographies. It was homogeneous on SDS-PAGE, with a molecular mass estimated to 35 kDa and presents a pI of 5.6. CcMP-II has an N-terminal sequence of EDRHINLVSVADHRMXTKY, with high levels of homology with those of the members of class P-II of SVMPs, which comprises metalloproteinase and disintegrin-like domains together. This proteinase displayed a fibrinogenolytic and hemorrhagic activities. The proteolytic and hemorrhagic activities of CcMP-II were inhibited by EDTA and 1,10-phenanthroline. However, these activities were not affected by aprotinine and PMSF, suggesting that CcMP-II is a zinc-dependent hemorrhagic metalloproteinase with an α-fibrinogenase activity. The hemorrhagic metalloproteinase CcMP-II was also able to hydrolyze extracellular matrix components, such as type IV collagen and laminin. These results indicate that CcMP-II is implicated in the local and systemic bleeding, contributing thus in the toxicity of C. cerastes venom.