Purification of therapeutic proteins mediated by in vivo polyester immobilized sortase

Objectives

To overcome laborious and costly procedures often associated with therapeutic protein production and purification, in vivo polyester immobilized sortase is explored for the production of human tumor necrosis factor alpha (TNFα) and human interferon alpha 2b (IFNα2b) by Escherichia coli.

Results

Hybrid genes encoding PhaC-Sortase-TNFα or PhaC-Sortase-IFNα2b fusions (with a LPETG recognition signal immediately before TNFα or IFNα2b), mediated intracellular production of polyester (polyhydroxyalkanoate, PHA) beads in Escherichia coli. Upon isolation of respective PHA beads, pure soluble TNFα or IFNα2b was released by activating sortase via addition of CaCl₂ and triglycine. TNFα and IFNα2b each were recognized by corresponding conformational antibodies in an ELISA assay.

Conclusions

In vivo polyester immobilized sortase could be exploited for production and purification of high-value therapeutic proteins without laborious and costly downstream processing.