ABSTRACT
This chapter reviews the effects of snake venom proteases for their ability to specifically activate factor V by limited proteolysis and, thereby, contribute to a hypercoagulable state after envenomation of the patient. Factor V is glycoprotein with a high molecular mass (Mr) that circulates in blood with little or no procoagulant activity. Human factor V is synthesized as single-chain protein composed of 2196-amino acid residues. Proteolytic cleavage sites in human factor V by thrombin (T) and the factor V activator from F. E. Russell's viper venom (RVV-V). The amino acids corresponding to the heavy chain, connecting region, and light chain of factor V are also indicated. The complete amino acid sequences of RVV-Vα and RVV-Vγ isolated from Russell's viper venom have been determined by automated Edman degradation sequencing of S-pyridylethylated derivatives of the proteins and their peptide fragments generated by either chemical or enzymatic cleavages.
