Nuclease enzyme purification by bacterial surface display technique

Recombinant protein technology is constantly being developed to facilitate the production of proteins and their effiency. Thus, amount of produced protein can be increased by this technique, and as a result, their costs decrease. One of the techniques frequently used to design recombinant protein is display technique. Fusion proteins can be targeted by the display technique and bind to the outer surface proteins of the cell or bacteriophage. The display technique is very useful in designing new proteins. Targeted protein isolation from any cell is a complex process because cells have many functionally or structurally different proteins. In this study, the display technique is used to purify the target protein which is synthesized by a recombinant E. coli. For this purpose, primers have been designed for lpp, ompA and spd1 genes. These genes were amplified and combined, then transferred in a plasmid and cloned into E. coli as a fusion protein. After that, E. coli membrane was isolated and the Spd1 enzyme was cleavaged by enterokinase. Then membrane proteins were removed by centrifugation, the purified Spd1 enzyme was visualized on SDS-PAGE gel. As a result, the purification of the streptodornase enzyme, which is used clinically, with bacterial display technique. By this way, it was produced recombinantly with a very fast way and low cost compared to other classical purification techniques. This method, developed in our labratory within the scope of our thesis, will be useful for many other hydrophilic, recombinant proteins.