- Thapa, A. and Han, W. and Simons, R. H. and Chilkoti, A. and Chi, E. Y. and Lopez, G. P., Effect of detergents on the thermal behavior of elastin-like polypeptides,
Biopolymers, vol. 99 no. 1
pp. 55--62 [doi] .
(last updated on 2013/06/21)
Elastin-like polypeptide (ELP) fusions have been designed to allow large-scale, nonchromatographic purification of many soluble proteins by using the inverse transition cycling (ITC) method; however, the sensitivity of the aqueous lower critical solubility phase transition temperature (Tt) of ELPs to the addition of cosolutes, including detergents, may be a potential hindrance in purification of proteins with surface hydrophobicity in such a manner. To identify detergents that are known to solubilize such proteins (e.g., membrane proteins) and that have little effect on the Tt of the ELP, we screened a number of detergents with respect to their effects on the Tt and secondary structures of a model ELP (denoted here as ELP180). We found that mild detergents (e.g., n-dodecyl-beta-D-maltoside, Triton-X100, and 3-[(3-cholamidopropyl) dimethylamino]-1-propanesulfonate) do not alter the phase transition behavior or structure (as probed by circular dichroism) of ELP180. This result is in contrast to previous studies that showed a strong effect of other detergents (e.g., sodium dodecylsulfate) on the Tt of ELPs. Our results clearly indicate that mild detergents do not preclude ITC-based separation of ELPs, and thus that ELP fusions may prove to be useful in the purification of detergent-solubilized recombinant hydrophobic proteins, including membrane proteins, which are otherwise notoriously difficult to extract and purify by conventional separation methods (e.g., chromatography). (c) 2012 Wiley Periodicals, Inc.