| AVS 56th International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterial Interfaces Poster Session I |
| Presenter: | T. Thapa, University of New Mexico |
| Authors: | T. Thapa, University of New Mexico S. Simons, University of New Mexico E. Chi, University of New Mexico A. Chilkoti, Duke University G.P. Lopez, University of New Mexico |
| Correspondent: | Click to Email |
Low column efficiency is a common problem associated with the affinity purification of surfactant solubilized membrane proteins synthesized in recombinant and cell free expression systems. Elastin-like polypeptide (ELP) tags, which have been designed to allow non-chromatographic purification of soluble proteins, offer a potential means to enable facile large-scale purification of detergent solubilized recombinant membrane proteins. However, the phase transition temperature (Tt) of ELPs is sensitive to the addition of cosolutes and many detergents increase the Tt of ELPs to temperatures greater than the thermal denaturation temperature of many proteins that are fused to the ELP, hence prohibiting their use for protein purification. To identify detergents that would satisfy the dual and potentially conflicting requirements of stabilizing membrane proteins fused to an ELP, we screened different detergents with respect to their effect on the Tt of ELP[V5A2G3-180]. We found that dodecyl maltoside (DDM), a detergent that is commonly used to solubilize recombinantly expressed membrane proteins, did not significantly alter the phase transition characteristics of ELPs or their structure as probed by a temperature-programmed turbidity assay and circular dichroism spectroscopy. Our results clearly indicate that DDM does not affect the inverse transition cycling of ELPs and therefore may be useful to purify membrane proteins which are otherwise difficult to extract and purify by affinity chromatography.