Molecular cloning of a serine beta-fibrinogenase homolog, a novel gene from russel's viper venom (Daboia Russellii Saimensis)

Abstract

Russell’s viper, RV, is a common venomous snake found in Thailand as well as South and Southeast Asian countries. RV venom consists of several digestive enzymes and proteins that affect coagulation. In this study, we cloned and characterized a novel serine beta-fibrinogenase homolog from RV venom gland cDNA library. Russell’s viper a full-length Serine beta-fibrinogenase (RV SBF) cDNA was cloned by revere-transcriptase polymerase chain reaction (RT-PCR) and 5’ rapid amplification of cDNA end (5’ RACE) into a plasmid vector from mRNA RV venom gland. The complete cDNA sequences was analyzed by PROSITE program, and predicted a 258-amino acids protein with 12 conserve cysteines internal forming 4 cysteines bond, with an N-terminal region of 18 amino acids signal peptide, 6 amino acids activation peptide and 234 amino acids mature protein. The sequence of RV SBF was compared to previously published snake venom SBF in the GENBANK database, and is 91% identical to Macrovipera lebetina serine beta-fibrinogenase. Using CLASTALX and MEGA 3.1 Program, a phylogenetic relationship between various vipers and other snake venom serine beta-fibrinogenase was constructed. These data is useful for future work on purification and recombinant expression of this protein.