Abstract
The effects of the channel-forming peptide gramicidin D (gD) on the conductance and electroporation thresholds of planar bilayer lipid membranes, made of the synthetic lipid 1-palmitoyl 2-oleoyl phosphatidylcholine (POPC), was studied. High-amplitude ( approximately 200-900 mV) rectangular voltage pulses of 15 ms duration were used to perturb the bilayers and monitor the transmembrane conductance. Electroporation voltage thresholds were found, and conductance was recorded before and after electroporation. Gramicidin was added to the system in peptide/lipid ratios of 1:10, 000, 1:500, and 1:15. The addition of gD in a ratio of 1:10,000 had no effect on electroporation, but ratios of 1:500 and 1:15 significantly increased the thresholds by 16% (p < 0.0001) and 40% (p < 0.0001), respectively. Membrane conductance before electroporation was measurable only after the addition of gD and increased monotonically as the peptide/lipid ratio increased. The effect of gD on the membrane area expansivity modulus (K) was tested using giant unilamellar vesicles (GUVs). When gD was incorporated into the vesicles in a 1:15 ratio, K increased by 110%, consistent with the increase in thresholds predicted by an electromechanical model. These findings suggest that the presence of membrane proteins may affect the electroporation of lipid bilayers by changing their mechanical properties.
Full Text
The Full Text of this article is available as a PDF (124.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andersen O. S. Ion movement through gramicidin A channels. Single-channel measurements at very high potentials. Biophys J. 1983 Feb;41(2):119–133. doi: 10.1016/S0006-3495(83)84414-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bamberg E., Läuger P. Channel formation kinetics of gramicidin A in lipid bilayer membranes. J Membr Biol. 1973;11(2):177–194. doi: 10.1007/BF01869820. [DOI] [PubMed] [Google Scholar]
- Bamberg E., Läuger P. Temperature-dependent properties of gramicidin A channels. Biochim Biophys Acta. 1974 Oct 29;367(2):127–133. doi: 10.1016/0005-2736(74)90037-6. [DOI] [PubMed] [Google Scholar]
- Chen W., Lee R. C. Altered ion channel conductance and ionic selectivity induced by large imposed membrane potential pulse. Biophys J. 1994 Aug;67(2):603–612. doi: 10.1016/S0006-3495(94)80520-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chernomordik L. V., Sukharev S. I., Popov S. V., Pastushenko V. F., Sokirko A. V., Abidor I. G., Chizmadzhev Y. A. The electrical breakdown of cell and lipid membranes: the similarity of phenomenologies. Biochim Biophys Acta. 1987 Sep 3;902(3):360–373. doi: 10.1016/0005-2736(87)90204-5. [DOI] [PubMed] [Google Scholar]
- Deamer D. W. Proton permeation of lipid bilayers. J Bioenerg Biomembr. 1987 Oct;19(5):457–479. doi: 10.1007/BF00770030. [DOI] [PubMed] [Google Scholar]
- Dimitrov D. S. Electric field-induced breakdown of lipid bilayers and cell membranes: a thin viscoelastic film model. J Membr Biol. 1984;78(1):53–60. doi: 10.1007/BF01872532. [DOI] [PubMed] [Google Scholar]
- Evans E., Kwok R. Mechanical calorimetry of large dimyristoylphosphatidylcholine vesicles in the phase transition region. Biochemistry. 1982 Sep 28;21(20):4874–4879. doi: 10.1021/bi00263a007. [DOI] [PubMed] [Google Scholar]
- Evans E., Needham D. Giant vesicle bilayers composed of mixtures of lipids, cholesterol and polypeptides. Thermomechanical and (mutual) adherence properties. Faraday Discuss Chem Soc. 1986;(81):267–280. doi: 10.1039/dc9868100267. [DOI] [PubMed] [Google Scholar]
- Evans E, Rawicz W. Entropy-driven tension and bending elasticity in condensed-fluid membranes. Phys Rev Lett. 1990 Apr 23;64(17):2094–2097. doi: 10.1103/PhysRevLett.64.2094. [DOI] [PubMed] [Google Scholar]
- Finkelstein A. Bilayers: formation, measurements, and incorporation of components. Methods Enzymol. 1974;32:489–501. doi: 10.1016/0076-6879(74)32049-6. [DOI] [PubMed] [Google Scholar]
- Girshman J., Greathouse D. V., Koeppe R. E., 2nd, Andersen O. S. Gramicidin channels in phospholipid bilayers with unsaturated acyl chains. Biophys J. 1997 Sep;73(3):1310–1319. doi: 10.1016/S0006-3495(97)78164-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall J. E. Access resistance of a small circular pore. J Gen Physiol. 1975 Oct;66(4):531–532. doi: 10.1085/jgp.66.4.531. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kozhomkulov E., Normatov K., Azimova Sh, Marzoev A. Modifikatsiia élektricheskikh kharakteristik bisloinykh lipidnykh membran vnutrimitokhondrial'nym retseptorom tireoidnykh gormonov. Probl Endokrinol (Mosk) 1984 Sep-Oct;30(5):60–63. [PubMed] [Google Scholar]
- Longo M. L., Waring A. J., Hammer D. A. Interaction of the influenza hemagglutinin fusion peptide with lipid bilayers: area expansion and permeation. Biophys J. 1997 Sep;73(3):1430–1439. doi: 10.1016/S0006-3495(97)78175-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Needham D., Hochmuth R. M. Electro-mechanical permeabilization of lipid vesicles. Role of membrane tension and compressibility. Biophys J. 1989 May;55(5):1001–1009. doi: 10.1016/S0006-3495(89)82898-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Needham D., Nunn R. S. Elastic deformation and failure of lipid bilayer membranes containing cholesterol. Biophys J. 1990 Oct;58(4):997–1009. doi: 10.1016/S0006-3495(90)82444-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neher E., Sandblom J., Eisenman G. Ionic selectivity, saturation, and block in gramicidin A channels. II. Saturation behavior of single channel conductances and evidence for the existence of multiple binding sites in the channel. J Membr Biol. 1978 Apr 26;40(2):97–116. doi: 10.1007/BF01871143. [DOI] [PubMed] [Google Scholar]
- Neher E., Stevens C. F. Conductance fluctuations and ionic pores in membranes. Annu Rev Biophys Bioeng. 1977;6:345–381. doi: 10.1146/annurev.bb.06.060177.002021. [DOI] [PubMed] [Google Scholar]
- Ohno-Shosaku T., Okada Y. Electric pulse-induced fusion of mouse lymphoma cells: roles of divalent cations and membrane lipid domains. J Membr Biol. 1985;85(3):269–280. doi: 10.1007/BF01871522. [DOI] [PubMed] [Google Scholar]
- Prosser R. S., Daleman S. I., Davis J. H. The structure of an integral membrane peptide: a deuterium NMR study of gramicidin. Biophys J. 1994 May;66(5):1415–1428. doi: 10.1016/S0006-3495(94)80932-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rols M. P., Teissie J. Ionic-strength modulation of electrically induced permeabilization and associated fusion of mammalian cells. Eur J Biochem. 1989 Jan 15;179(1):109–115. doi: 10.1111/j.1432-1033.1989.tb14527.x. [DOI] [PubMed] [Google Scholar]
- Rosemberg Y., Rotenberg M., Korenstein R. Electroporation of the photosynthetic membrane: structural changes in protein and lipid-protein domains. Biophys J. 1994 Sep;67(3):1060–1066. doi: 10.1016/S0006-3495(94)80571-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sharma V., Stebe K., Murphy J. C., Tung L. Poloxamer 188 decreases susceptibility of artificial lipid membranes to electroporation. Biophys J. 1996 Dec;71(6):3229–3241. doi: 10.1016/S0006-3495(96)79516-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Troiano G. C., Tung L., Sharma V., Stebe K. J. The reduction in electroporation voltages by the addition of a surfactant to planar lipid bilayers. Biophys J. 1998 Aug;75(2):880–888. doi: 10.1016/S0006-3495(98)77576-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsong T. Y. Electroporation of cell membranes. Biophys J. 1991 Aug;60(2):297–306. doi: 10.1016/S0006-3495(91)82054-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Veatch W. R., Mathies R., Eisenberg M., Stryer L. Simultaneous fluorescence and conductance studies of planar bilayer membranes containing a highly active and fluorescent analog of gramicidin A. J Mol Biol. 1975 Nov 25;99(1):75–92. doi: 10.1016/s0022-2836(75)80160-4. [DOI] [PubMed] [Google Scholar]
- Wiley J. D., Webster J. G. Analysis and control of the current distribution under circular dispersive electrodes. IEEE Trans Biomed Eng. 1982 May;29(5):381–385. doi: 10.1109/TBME.1982.324910. [DOI] [PubMed] [Google Scholar]
- Woolf T. B., Roux B. Molecular dynamics simulation of the gramicidin channel in a phospholipid bilayer. Proc Natl Acad Sci U S A. 1994 Nov 22;91(24):11631–11635. doi: 10.1073/pnas.91.24.11631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhelev D. V. Exchange of monooleoylphosphatidylcholine with single egg phosphatidylcholine vesicle membranes. Biophys J. 1996 Jul;71(1):257–273. doi: 10.1016/S0006-3495(96)79222-6. [DOI] [PMC free article] [PubMed] [Google Scholar]