Cell disruption enhanced the pure EGFP recovery from an EGFP-intein-surface protein production system in recombinant E. coli

In this study, three approaches for protein production were devised to enhance the efficiencies in yielding high purity protein via surface display system. A plasmid carrying enhanced green fluorescent protein (EGFP), an intein (INT) and ice nucleation protein (INP) was constructed to produce EGFP via surface display in Escherichia coli. To obtain high purity of the produced EGFP, several procedures, including osmotic shock, surfactant addition and cell disruption were employed. Among these approaches, the cell disruption method gave the highest EGFP purity by simply conducting several centrifugations. An EGFP yield of 63 mg/L with 97% purity was obtained. The result demonstrated that pure EGFP can be harvested only through centrifugation; no complicated processes or expensive equipment are required. This approach shows potential for the production of pure recombinant proteins in scale-up processes for biotechnological, academic and industrial uses.

► Approach to obtain highly pure EGFP by INP-INT system was developed. ► Osmotic shock method gave the highest EGFP yield. ► Cell disruption method gave the highest EGFP purity by only centrifugations. ► An EGFP yield of 63 mg/L with 97% purity was obtained via cell disruption method. ► This approach is useful for pure recombinant protein production in large scale.