Interfacial properties of the M1 segment of the nicotinic acetylcholine receptor

AMBROGGIO, ERNESTO E.; VILLARREAL, MARCOS A.; MONTICH, GUILLERMO G.; RIJKERS, DIRK TS; DE PLANQUE, MAURITS R.R.; SEPAROVIC, FRANCES; FIDELIO, GERARDO D.

ELSEVIER SCIENCE BV

Año: 2006 vol. 121 p. 171 - 171

e have studied the thermodynamic, surface, and structural properties of αM1 transmembrane sequence of the nicotinic acetylcholine receptor (nAChR) by using Langmuir monolayer, FT-IR spectroscopy and molecular dynamics simulation techniques in membrane-mimicking environments. M1 spontaneously incorporates into a lipid-free air–water interface, showing a favourable adsorption free energy of −7.2 kcal/mol. A cross-sectional molecular area of 210 Å 2 /molecule, a surface potential of 4.2 fV/molecule and a high stability of the film were deducted from pure M1 monolayers. FT-IR experiments and molecular dynamics simulations in membrane-mimicking environments (sodium-dodecyl-sulfate and CCl4, respectively) indicate coexistence between helical and non-helical structures. Furthermore, mixed peptide–lipid monolayers and monolayer penetration experiments were performed in order to study the peptide–lipid interaction. Mixed with condensed lipids (dipalmitoylphosphocholine, and