Isolation and Functional Identification of an Antiplatelet RGD-Containing Disintegrin fromCerastes cerastesVenom

The current report focuses on purification, structural and functional characterization of Cerastategrin fromCerastes cerastesvenom, a novel basic disintegrin (pI 8.36) with 128 amino acid residues and a molecular weight of 13 835.25 Da measured by MALDI-MSMS. The 3D structure of Cerastategrin is organized as alpha-helix (13%), beta-strand (15%) and disordered structure (30%) and presents homologies with several snake venom disintegrins. Structural modeling shows that Cerastategrin presents an RGD motif that connects specifically to integrin receptors. Cerastategrin exhibits the inhibition of ADP induced platelets with an IC(50)of 0.88 mu g/mL and shows in vivo long stable anticoagulation effect 24 h post-injection of increasing doses ranging from 0.2 to 1 mg/kg, therefore, Cerastategrin maintained irreversibly the blood incoagulable. Moreover, Cerastategrin decreases the amount of bounded alpha IIb beta 3 and reduced significantly the quantity of externalized P-Selectin. Cerastategrin acts as a molecule targeting specifically the receptor alpha(IIb)beta(3); therefore, it behaves as a potent platelet activation inhibitor. As a new peptide with promising pharmacological properties, Cerastategrin could have a potential therapeutical effect in the vascular pathologies and may be a new effective treatment approach.