Effect of ions on phospholipid layer structure as indicated by Raman spectroscopy.
Various anions and cations are found to induce changes in the layered structure of phosphatidylcholine-water systems as indicated by Raman Spectroscopy. From the ratio of Raman intensities, I1064/I1089, it is inferred that dipositive ions decrease the proportion of gauche character in the hydrocarbon chains, with the relative influence being: Ba2+ less than Mg2+ less than Ca2+ similar to Cd2+. Unipositive ions (Li+, K+ and Na+) produce no observed changes in the Raman spectrum of the lecithin dispersion. The proportion of gauche character of the hydrocarbon chains is found to be nearly independent of the anion for: Br-, Cl-, acetate-, I-, ClO4-, CNS- and SO42-. Dispersions prepared with a solution of KI+I2 produced Raman spectra in which the 1089cm-1 peak, which is characteristic of random lipid chains, was greatly intensified, presumably because of the presence of I3- which is known to penetrate the lipid lamellae. The observed trends are discussed.
D000838:Anions; D002413:Cations, Divalent; D002414:Cations, Monovalent; D005227:Fatty Acids; D006863:Hydrogen-Ion Concentration; D007454:Iodides; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D012542:Scattering, Radiation; D013057:Spectrum Analysis
D000838:Anions; D002413:Cations, Divalent; D002414:Cations, Monovalent; D005227:Fatty Acids; D007454:Iodides; D008567:Membranes, Artificial; D010713:Phosphatidylcholines