Effects of Positively Charged Lipids on Interfacial Behavior in Spread Monolayers: Thermodynamic Studies with DOCA, a Synthetic Lipid
✍ Scribed by A.-F. Mingotaud; L.K. Patterson
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 279 KB
- Volume
- 157
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
A positively charged lipid, dioleoyl- (N)-( 3 -trimethylammonio propyl) carbamoyl glycerol chloride, DOCA, has been synthesized in order to obtain a cationic compound which mimics as closely as possible the behavior of naturally occurring phospholipids on monolayers. This compound has been shown to form liquid phase monolayers with thermodynamic characteristics comparable to those of related phospholipids. Surface pressurearea studies in mixtures with a negatively charged lipid indicate excellent miscibility and a very pronounced excess free energy of mixing. Fluorescence quenching studies demonstrate a pronounced association of the water-soluble anion, (\mathrm{I}^{-}), at the DOCA headgroup from very dilute iodide subphase concentrations. This behavior suggests a very high surface potential generated by the cationic headgroup in DOCA. 1993 Academic Press, nnc.