On-column refolding purification of DT389-hIL13 recombinant protein expressed in Escherichia coli.

Protein refolding is a bottleneck in the production of therapeutic proteins from inclusion bodies. In recent years, several studies have described on-column refolding of recombinant proteins. DT389-hIL13 is a recombinant protein that targets the glioma. In our study, the recombinant protein DT389-hIL13 was expressed in Escherichia coli (E. coli). The isolated inclusion bodies were refolded using size exclusion chromatography (SEC) and further purified using anion exchange chromatography. Three different methods of SEC on-column refolding were studied. In vitro tests on U251 cells showed that the recombinant protein could effectively inhibit the proliferation of U251 cells, especially the protein refolded by urea and pH gradient method. The half-maximal inhibitory concentration (IC50) of 0.887 nM was achieved with this new method, unlike an IC50 of 11.4 nM achieved in the non-gradient method.