title: Effect of detergents on the thermal behavior of elastin-like polypeptides.
abstract: 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 (T(t)) 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 T(t) of the ELP, we screened a number of detergents with respect to their effects on the T(t) and secondary structures of a model ELP (denoted here as ELP180). We found that mild detergents (e.g., n-dodecyl-β-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 T(t) 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).
authors.affiliation: Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM.
authors.forename: Arjun
authors.initials: A
authors.lastname: Thapa
authors.forename: Wei
authors.initials: W
authors.lastname: Han
authors.forename: Robin H
authors.initials: RH
authors.lastname: Simons
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Chilkoti
authors.forename: Eva Y
authors.initials: EY
authors.lastname: Chi
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: López
mesh_terms: D002942:Circular Dichroism; D003902:Detergents / Q000737:chemistry*; D004549:Elastin / Q000737:chemistry*; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012995:Solubility; D013696:Temperature
chemical_list: D003902:Detergents; D010455:Peptides; D004549:Elastin