Purification and Characterization of Annexin Ⅱ Related Protein from Bombina maxina Skin

A single chain protein with an apparent molecular weight of 33 kDa was purified from skin of Bombina maxima by a combination of ion exchange and gel filtration chromatography steps. N-terminal amino acid sequence determination indicated that it shares 70%, 64% and 56% identity with those of annexin Ⅱ from the African claw toad, red jungle fowl and human, respectively. The purified protein from B. maxina inhibits stejnulxin (a specific platelet agonist via platelet membrane glycoprotein Ⅵ receptor) induced platelet aggregation in a Ca2+ dependent manner. Maximal inhibition rate reaches 48%. Based on the N-terminal amino acid sequence BLAST search results and the fact that its activity is strictly Ca2+ dependent, the purified protein might be structurally and functionally related to the annexin protein family.