Abstract
We have investigated the influence of pH on the structures and phase behaviors of multilamellar vesicles of the ether-linked dihexadecylphosphatidylcholine (DHPC-MLV). This phospholipid is known to be in the interdigitated gel (L(beta)I) phase in excess water at 20 degrees C at neutral pH. The results of X-ray diffraction experiments indicate that a phase transition from L(beta)I phase to the bilayer gel phase occurred in DHPC-MLV in 0.5 M KCl around pH 3.9 with a decrease in pH, and that at low pH values, less than pH 2.2, DHPC-MLVs were in L(beta') phase. The results of fluorescence and light scattering method indicate that the gel to liquid-crystalline phase transition temperature (T(m)) of DHPC-MLV increased with a decrease in pH. On the basis of a thermodynamic analysis, we conclude that the main mechanism of the low-pH induced L(beta)I to bilayer gel phase transition in DHPC-MLV and the increase in its T(m) is connected with the decrease in the repulsive interaction between the headgroups of these phospholipids. As pH decreases, the phosphate groups of the headgroups begin to be protonated, and as a result, the apparent positive surface charges appear. However, surface dipoles decrease and the interaction free energy of the hydrophilic segments with water increases. The latter effect dominates the pure electrostatic repulsion between the charged headgroups, and thereby, the total repulsive interaction in the interface decreases.
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- Adachi T., Takahashi H., Ohki K., Hatta I. Interdigitated structure of phospholipid-alcohol systems studied by x-ray diffraction. Biophys J. 1995 May;68(5):1850–1855. doi: 10.1016/S0006-3495(95)80361-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BARTLETT G. R. Phosphorus assay in column chromatography. J Biol Chem. 1959 Mar;234(3):466–468. [PubMed] [Google Scholar]
- Bechinger B., Seelig J. Interaction of electric dipoles with phospholipid head groups. A 2H and 31P NMR study of phloretin and phloretin analogues in phosphatidylcholine membranes. Biochemistry. 1991 Apr 23;30(16):3923–3929. doi: 10.1021/bi00230a017. [DOI] [PubMed] [Google Scholar]
- Cevc G., Watts A., Marsh D. Titration of the phase transition of phosphatidylserine bilayer membranes. Effects of pH, surface electrostatics, ion binding, and head-group hydration. Biochemistry. 1981 Aug 18;20(17):4955–4965. doi: 10.1021/bi00520a023. [DOI] [PubMed] [Google Scholar]
- Fattal D. R., Ben-Shaul A. A molecular model for lipid-protein interaction in membranes: the role of hydrophobic mismatch. Biophys J. 1993 Nov;65(5):1795–1809. doi: 10.1016/S0006-3495(93)81249-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frischleder H., Gleichmann S., Krahl R. Quantum-chemical and empirical calculations on phospholipids, III. Hydration of the dimethylphosphate anion. Chem Phys Lipids. 1977 Jun;19(2):144–149. doi: 10.1016/0009-3084(77)90094-9. [DOI] [PubMed] [Google Scholar]
- Hatanaka Y., Kinoshita K., Yamazaki M. Osmotic stress induces a phase transition from interdigitated gel phase to bilayer gel phase in multilamellar vesicles of dihexadecylphosphatidylcholine. Biophys Chem. 1997 Apr 22;65(2-3):229–233. doi: 10.1016/s0301-4622(97)00004-5. [DOI] [PubMed] [Google Scholar]
- Huang C., McIntosh T. J. Probing the ethanol-induced chain interdigitations in gel-state bilayers of mixed-chain phosphatidylcholines. Biophys J. 1997 Jun;72(6):2702–2709. doi: 10.1016/S0006-3495(97)78913-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Israelachvili J. N., Marcelja S., Horn R. G. Physical principles of membrane organization. Q Rev Biophys. 1980 May;13(2):121–200. doi: 10.1017/s0033583500001645. [DOI] [PubMed] [Google Scholar]
- Jähnig F., Harlos K., Vogel H., Eibl H. Electrostatic interactions at charged lipid membranes. Electrostatically induced tilt. Biochemistry. 1979 Apr 17;18(8):1459–1468. doi: 10.1021/bi00575a012. [DOI] [PubMed] [Google Scholar]
- Kim J. T., Mattai J., Shipley G. G. Gel phase polymorphism in ether-linked dihexadecylphosphatidylcholine bilayers. Biochemistry. 1987 Oct 20;26(21):6592–6598. doi: 10.1021/bi00395a005. [DOI] [PubMed] [Google Scholar]
- Kinoshita K., Furuike S., Yamazaki M. Intermembrane distance in multilamellar vesicles of phosphatidylcholine depends on the interaction free energy between solvents and the hydrophilic segments of the membrane surface. Biophys Chem. 1998 Sep 14;74(3):237–249. doi: 10.1016/s0301-4622(98)00191-4. [DOI] [PubMed] [Google Scholar]
- Kinoshita K., Yamazaki M. Organic solvents induce interdigitated gel structures in multilamellar vesicles of dipalmitoylphosphatidylcholine. Biochim Biophys Acta. 1996 Oct 23;1284(2):233–239. doi: 10.1016/s0005-2736(96)00136-8. [DOI] [PubMed] [Google Scholar]
- Laggner P., Lohner K., Degovics G., Müller K., Schuster A. Structure and thermodynamics of the dihexadecylphosphatidylcholine-water system. Chem Phys Lipids. 1987 Jun;44(1):31–60. doi: 10.1016/0009-3084(87)90004-1. [DOI] [PubMed] [Google Scholar]
- Lewis R. N., Pohle W., McElhaney R. N. The interfacial structure of phospholipid bilayers: differential scanning calorimetry and Fourier transform infrared spectroscopic studies of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine and its dialkyl and acyl-alkyl analogs. Biophys J. 1996 Jun;70(6):2736–2746. doi: 10.1016/S0006-3495(96)79843-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Löbbecke L., Cevc G. Effects of short-chain alcohols on the phase behavior and interdigitation of phosphatidylcholine bilayer membranes. Biochim Biophys Acta. 1995 Jul 6;1237(1):59–69. doi: 10.1016/0005-2736(95)00076-f. [DOI] [PubMed] [Google Scholar]
- Marsh D. Lateral pressure in membranes. Biochim Biophys Acta. 1996 Oct 29;1286(3):183–223. doi: 10.1016/s0304-4157(96)00009-3. [DOI] [PubMed] [Google Scholar]
- McIntosh T. J. Differences in hydrocarbon chain tilt between hydrated phosphatidylethanolamine and phosphatidylcholine bilayers. A molecular packing model. Biophys J. 1980 Feb;29(2):237–245. doi: 10.1016/S0006-3495(80)85128-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rowe E. S., Campion J. M. Alcohol induction of interdigitation in distearoylphosphatidylcholine: fluorescence studies of alcohol chain length requirements. Biophys J. 1994 Nov;67(5):1888–1895. doi: 10.1016/S0006-3495(94)80671-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Simon S. A., McIntosh T. J. Interdigitated hydrocarbon chain packing causes the biphasic transition behavior in lipid/alcohol suspensions. Biochim Biophys Acta. 1984 Jun 13;773(1):169–172. doi: 10.1016/0005-2736(84)90562-5. [DOI] [PubMed] [Google Scholar]
- Slater J. L., Huang C. H. Interdigitated bilayer membranes. Prog Lipid Res. 1988;27(4):325–359. doi: 10.1016/0163-7827(88)90010-0. [DOI] [PubMed] [Google Scholar]
- Takahashi H., Ohmae H., Hatta I. Trehalose-induced destabilization of interdigitated gel phase in dihexadecylphosphatidylcholine. Biophys J. 1997 Dec;73(6):3030–3038. doi: 10.1016/S0006-3495(97)78331-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tocanne J. F., Teissié J. Ionization of phospholipids and phospholipid-supported interfacial lateral diffusion of protons in membrane model systems. Biochim Biophys Acta. 1990 Feb 28;1031(1):111–142. doi: 10.1016/0304-4157(90)90005-w. [DOI] [PubMed] [Google Scholar]
- Tyäuble H., Teubner M., Woolley P., Eibl H. Electrostatic interactions at charged lipid membranes. I. Effects of pH and univalent cations on membrane structure. Biophys Chem. 1976 Jul;4(4):319–342. doi: 10.1016/0301-4622(76)80013-0. [DOI] [PubMed] [Google Scholar]
- Vierl U., Löbbecke L., Nagel N., Cevc G. Solute effects on the colloidal and phase behavior of lipid bilayer membranes: ethanol-dipalmitoylphosphatidylcholine mixtures. Biophys J. 1994 Sep;67(3):1067–1079. doi: 10.1016/S0006-3495(94)80572-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Watts A., Harlos K., Marsh D. Charge-induced tilt in ordered-phase phosphatidylglycerol bilayers evidence from X-ray diffraction. Biochim Biophys Acta. 1981 Jul 6;645(1):91–96. doi: 10.1016/0005-2736(81)90515-0. [DOI] [PubMed] [Google Scholar]
- Yamazaki M., Miyazu M., Asano T., Yuba A., Kume N. Direct evidence of induction of interdigitated gel structure in large unilamellar vesicles of dipalmitoylphosphatidylcholine by ethanol: studies by excimer method and high-resolution electron cryomicroscopy. Biophys J. 1994 Mar;66(3 Pt 1):729–733. doi: 10.1016/s0006-3495(94)80848-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yamazaki M., Ohnishi S., Ito T. Osmoelastic coupling in biological structures: decrease in membrane fluidity and osmophobic association of phospholipid vesicles in response to osmotic stress. Biochemistry. 1989 May 2;28(9):3710–3715. doi: 10.1021/bi00435a013. [DOI] [PubMed] [Google Scholar]
- Yamazaki M., Ohshika M., Kashiwagi N., Asano T. Phase transitions of phospholipid vesicles under osmotic stress and in the presence of ethylene glycol. Biophys Chem. 1992 May;43(1):29–37. doi: 10.1016/0301-4622(92)80039-8. [DOI] [PubMed] [Google Scholar]
