6533b7d3fe1ef96bd12613ea

RESEARCH PRODUCT

Unfolding a transmembrane helix dimer: A FRET study in mixed micelles

Veerappan AnbazhaganFlorian CymerDirk Schneider

subject

DimerBiophysicsBiochemistryMicelleProtein Structure SecondarySurface-Active Agentschemistry.chemical_compoundFluorescence Resonance Energy TransferHumansGlycophorinGlycophorinsMolecular BiologyMicellesbiologyChemistryPeripheral membrane proteinSodium Dodecyl SulfateTransmembrane proteinProtein Structure TertiaryKineticsTransmembrane domainCrystallographyFörster resonance energy transferMembrane proteinbiology.proteinProtein Multimerization

description

The exact nature of membrane protein folding and assembly is not understood in detail yet. Addition of SDS to a membrane protein dissolved in mild, non-polar detergent results in formation of mixed micelles and in subsequent denaturation of higher ordered membrane protein structures. The exact nature of this denaturation event is, however, enigmatic, and separation of an individual helix pair in mixed micelles has also not been reported yet. Here we followed unfolding of the human glycophorin A transmembrane helix dimer in mixed micelles by fluorescence spectroscopy. Energy transfer between differently labelled glycophorin A transmembrane helices decreased with increasing SDS mole fractions albeit without modifying the helicity of the peptides. The energetics and kinetics of the dimer dissociation in mixed micelles is analyzed and discussed, and the experimental data demonstrate that mixed micelles can be used as a general method to investigate unfolding of alpha-helical membrane proteins.

yearjournalcountryeditionlanguage
2009-11-26Archives of Biochemistry and Biophysics
https://doi.org/10.1016/j.abb.2010.01.006