On-column refolding purification of DT389-hIL13 recombinant protein expressed in Escherichia coli.
ABSTRACT 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.
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Conference Proceeding: Polarization bistability of vertical cavity lasers under external optical injection[show abstract] [hide abstract]
ABSTRACT: The polarization bistability of VCLs is studied theoretically with the consideration of dielectric Bragg reflectors, surface coatings, carrier induced refractive index inside the active layer as well as the intensity and wavelength of the injected light. The VCL has a built-in index guided structure and a GaAs-Al<sub>0.3</sub>Ga<sub>0.7</sub>As quantum well active layer. A rate-equation model is developed. It is shown that all-optical switching and memory operation can be achieved in VCLs by external optical injection, however, devices with suitable design of surface coating and Bragg reflectors are requiredLasers and Electro-Optics Society Annual Meeting, 1996. LEOS 96., IEEE; 12/1996