CLONING, EXPRESSION AND BIOASSAY OF CRY 2AX PROTEIN WITH AND WITHOUT TAG IN ESCHERICHIA COLI AGAINST HELICOVERPA ARMIGERA AND SPODOPTERA LITURA

Abstract

– Proteins are highly unstable and loose biological activity if not frozen under -4 o C to 20 o C. Naturally, every biological system has its own protective mechanism to maintain the biological function of each protein such as chaperones. In case of recombinant protein synthesis, no such mechanism has been observed. In this experiment a synthetic gene Cry 2Ax from Bacillus thuringiensis ( Bt ) was isolated and transformed into Escherichia coli strain with and without tag (His tag and Fusion tag) to know the expression pattern. pET 28a is used as a vector plasmid. The experimental results revealed that the tagged recombinant yielded more protein (1.5 to 2.0 µg / µl) compared with non tagged system (0.6 to 0.8 µg/µl). It shows the positive role of fusion tags on protection and expression (three fold) of the recombinant protein.