We report on the infrared spectra of binary di-palmitoyl-phosphatidyl-ethanolamine-cardiolipin (DPPE1-xCLPx) monolayers and multilamellar vesicles as a function of CLP molar fraction x and temperature T. These data, which clearly show the presence of, at least, two kind of lipid domains with different thermodynamic stability and ordering of the lipid acyl chains, are consistent with similar domains observed in Langmuir-Blodgett films of the same binary system. Infrared results suggest the presence of lateral phase separation phenomena both in the bilayers and in the monolayers build up with this binary lipid mixture. These results further support the hypothesis that, within these structures, DPPE1-xCLPx molecules, for given values of x, are organized in a superlattice as shown by thermodynamic and AFM measurements. (C) 2008 Elsevier B.V. All rights reserved.
Infrared spectra of phosphatidylethanolamine-cardiolipin binary system
Lupi S;Maselli P;Bordi F;Sennato S
2008
Abstract
We report on the infrared spectra of binary di-palmitoyl-phosphatidyl-ethanolamine-cardiolipin (DPPE1-xCLPx) monolayers and multilamellar vesicles as a function of CLP molar fraction x and temperature T. These data, which clearly show the presence of, at least, two kind of lipid domains with different thermodynamic stability and ordering of the lipid acyl chains, are consistent with similar domains observed in Langmuir-Blodgett films of the same binary system. Infrared results suggest the presence of lateral phase separation phenomena both in the bilayers and in the monolayers build up with this binary lipid mixture. These results further support the hypothesis that, within these structures, DPPE1-xCLPx molecules, for given values of x, are organized in a superlattice as shown by thermodynamic and AFM measurements. (C) 2008 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
