ISOLATION, CHARACTERIZATION AND AMINO-ACID-SEQUENCE OF ECHICETIN BETA-SUBUNIT, A SPECIFIC INHIBITOR OF VON-WILLEBRAND-FACTOR AND THROMBIN INTERACTION WITH GLYCOPROTEIN 1B

Echicetin is a dimeric protein isolated from the venom of Echis carina tus that is a potent inhibitor of von Willebrand Factor and thrombin b inding to glycoprotein Ib. Here, we report isolation and amino acid se quence of the beta subunit of echicetin that contains 123 amino acids, including 7 cysteines, and shows similarity with amino acid sequences of botrocetin and Factor IXa/Xa binding protein. We provide evidence that biological activity of echicetin which resides in this beta subun it is relatively resistant to reduction of the molecule. (C) 1994 Acad emic Press, Inc.