Membrane fluidity response to odorants as seen by 2H-NMR and infrared spectroscopy.
Fourier transform infrared spectroscopy (FTIR) and deuterium nuclear magnetic resonance spectroscopy (2H-NMR) have been used to study the location of two odorants, beta-ionone and menthone, in a model membrane of dimyristoylphosphatidylcholine, as well as the effect of the odorants on the structure and dynamics of the phospholipids. The interaction has been investigated for two lipid-to-odorant molar ratios, 10:1 and 1:1. The two odorants were found to affect the fluidity of the membrane. More specifically, the 2H-NMR results indicate that at a lipid-to-odorant molar ratio of 10:1, both beta-ionone and menthone increase the order of the deuterons in the interfacial and headgroup regions of the lipid while the incorporation of the odorants at a lipid-to-odorant molar ratio of 1:1 decreases the order of both the lipid headgroup and acyl chains. On the other hand, the infrared results show that the incorporation of beta-ionone and menthone decreases the phase transition temperature and cooperativity of the lipid acyl chains. The results suggest that the site of incorporation of beta-ionone and menthone is very similar in DMPC membranes.
Bouchard
M
M
Département de Chimie, Université Laval, Québec, Canada.
Boudreau
N
N
Auger
M
M
D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008560:Membrane Fluidity / Q000187:drug effects*; D008610:Menthol; D045792:Norisoprenoids; D009812:Odorants; D018035:Receptors, Odorant; D017550:Spectroscopy, Fourier Transform Infrared; D013729:Terpenes / Q000494:pharmacology*
D008081:Liposomes; D045792:Norisoprenoids; D018035:Receptors, Odorant; D013729:Terpenes; D008610:Menthol; C019466:menthone; C008157:beta-ionone; D004134:Dimyristoylphosphatidylcholine