The Thermodynamic Stability of Membrane Proteins in Micelles and Lipid Bilayers Investigated with the Ferrichrom Receptor FhuA.

ABSTRACT: Extraction of integral membrane proteins into detergents for structural and functional studies often leads to a strong loss in protein stability. The impact of the lipid bilayer on the thermodynamic stability of an integral membrane protein in comparison to its solubilized form in detergent was examined and compared for FhuA from Escherichia coli and for a mutant, FhuAΔ5-160, lacking the N-terminal cork domain. Urea-induced unfolding was monitored by fluorescence spectroscopy to determine the effective free energies [Formula: see text] of unfolding. To obtain enthalpic and entropic contributions of unfolding of FhuA, [Formula: see text] were determined at various temperatures. When solubilized in LDAO detergent, wt-FhuA and FhuAΔ5-160 unfolded in a single step. The 155-residue cork domain

SUBMITTER: Pocanschi CL 

PROVIDER: S-EPMC9581862 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature