[Construction of an expression vector with elastin-like polypeptide tag to purify xylanase].

ABSTRACT

OBJECTIVE: This paper reports the purification of xylanase using the shortest, sensitive ELP [KV8F-20]. METHODS: We designed a thermophilic xylanase gene, and recombined it with the ELP via a random coil sequence to generate the vector pET-22b-SoxB-M2-S-ELP. The expressed xylanase was purified by inverse transition cycling through high-speed centrifugation, and then we characterized the purified xylanase. RESULTS: The phase transition temperature of the ELPs dropped to 22 degrees C with 0.5 mol/L sodium carbonate (pH = 7). Under this condition, SoxB-M2-S-ELP was purified by 3.16 folds after centrifugation. The recovery rate was 21.2%, and purity of the xylanase was 64.3%. CONCLUSION: Elastin-like polypeptide as a purification tag to purify recombinant proteins is simple, fast, gentle and cheaper. The expression vector we constructed here might be a very useful and reliable tool to purify many other target proteins.