Gene Cloning and Sequence Analysis of Defibrasefrom Gloydius ussuriensis Snake

Objective:To clone gene sequence of defibrase from venom gland of Gloidius ussuriensis and gett gene product of defibrase in the future. Methods:Total RNAs were extracted from the venom gland of the Gloydins Ussurisis snake.The thrombin like enzyme gene was amplified by RT PCR, cloned, and its nucleotide sequences had been determined.Results:The enzyme called defibrase cDNA encodes 702 nucleotides, namely 234 amino acids. Based on the homology, the catalytic residues and disulfide bridges of defibrase were deduced as followings: catalytic residues, His 41 ,Asp 86 , Ser 180 and six disulfide bridges. Conclusion:cDNA sequence of defibrase was proved, amino acid sequence and structure of active center were deduced.