Electrostatic interactions in phospholipid membranes revealed by coherent 2D IR spectroscopy.
The inter- and intramolecular interactions of the carbonyl moieties at the polar interface of a phospholipid membrane are probed by using nonlinear femtosecond infrared spectroscopy. Two-dimensional IR correlation spectra separate homogeneous and inhomogeneous broadenings and show a distinct cross-peak pattern controlled by electrostatic interactions. The inter- and intramolecular electrostatic interactions determine the inhomogeneous character of the optical response. Using molecular dynamics simulation and the nonlinear exciton equations approach, we extract from the spectra short-range structural correlations between carbonyls at the interface.
Volkov
V V
VV
European Laboratory for Nonlinear Spectroscopy, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy. vvolkov@lens.unifi.it
Chelli
R
R
Zhuang
W
W
Nuti
F
F
Takaoka
Y
Y
Papini
A M
AM
Mukamel
S
S
Righini
R
R
D016880:Anisotropy; D002244:Carbon / Q000737:chemistry; D003198:Computer Simulation; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry; D015233:Models, Statistical; D008968:Molecular Conformation; D010743:Phospholipids / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013055:Spectrophotometry, Infrared / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
D008051:Lipid Bilayers; D010743:Phospholipids; D002244:Carbon