The specificity of ionophore A23187 in cation transport across lipid membranes. Studies with lecithin vesicles
- PMID: 6774496
- DOI: 10.1515/znc-1980-7-807
The specificity of ionophore A23187 in cation transport across lipid membranes. Studies with lecithin vesicles
Abstract
Lecithin vesicles containing different cations were prepared by sonication and characterized. When the concentration of the divalent cations in the buffer was increased from 1 mM to about 100 mM the cation-concentration inside of the vesicles did not increase proportional to the outside concentration, but showed a saturation behaviour. The efflux of various cations mediated by ionophore A23187 was measured and relative transport-rates were determined. The following sequence was obtained: Zn2+ > Ca2+ > Mg2+ > Sr2+ > Ba2+ approximately Li+ > Na+. The efflux of Ca2+ increased proportional to the square of the A23187-concentration. To lecithin-vesicles containing ethylenediamine tetraacetate (EDTA) inside different cations were added on the outside. In the presence of A23187 divalent cations are transported into the vesicles and bound there by EDTA. During the influx of Me2+-ions into vesicles a H+-efflux was observed. The resulting pH-decrease was measured. The rate of the pH-change depended on the Me2+-ion used. The sequence was: Cd2+ > Zn2+ > Ca2+ > Mn2+ > MG2+ > Sr2+, Ba2+.
Similar articles
-
Fluorescence study of the divalent cation-transport mechanism of ionophore A23187 in phospholipid membranes.Biophys J. 1981 Nov;36(2):369-91. doi: 10.1016/S0006-3495(81)84738-8. Biophys J. 1981. PMID: 6796150 Free PMC article.
-
Ionophore 4-BrA23187 transports Zn2+ and Mn2+ with high selectivity over Ca2+.Biochemistry. 1996 Oct 29;35(43):13817-25. doi: 10.1021/bi961391q. Biochemistry. 1996. PMID: 8901524
-
Ionophore A23187: the effect of H+ concentration on complex formation with divalent and monovalent cations and the demonstration of K+ transport in mitochondria mediated by A23187.Biochemistry. 1976 Mar 9;15(5):935-43. doi: 10.1021/bi00650a001. Biochemistry. 1976. PMID: 3212
-
Selective transport of Pb2+ and Cd2+ across a phospholipid bilayer by a cyclohexanemonocarboxylic acid-capped 15-crown-5 ether.J Inorg Biochem. 2006 Mar;100(3):403-12. doi: 10.1016/j.jinorgbio.2006.01.003. J Inorg Biochem. 2006. PMID: 16488017
-
Equilibria between ionophore A23187 and divalent cations: stability of 1:1 complexes in solutions of 80% methanol/water.Biochemistry. 1987 Aug 11;26(16):5009-18. doi: 10.1021/bi00390a019. Biochemistry. 1987. PMID: 3117110
Cited by
-
K+:Cl- cotransport: sulfhydryls, divalent cations, and the mechanism of volume activation in a red cell.J Membr Biol. 1985;88(1):1-13. doi: 10.1007/BF01871208. J Membr Biol. 1985. PMID: 3937898 Review. No abstract available.
-
Transport of potassium ions across planar lipid membranes by the antibiotic, grisorixin: I. The equilibrium state and self-diffusion K+ fluxes.J Membr Biol. 1985;88(1):15-23. doi: 10.1007/BF01871209. J Membr Biol. 1985. PMID: 4093953
-
Ca2+ transport properties of ionophores A23187, ionomycin, and 4-BrA23187 in a well defined model system.Biophys J. 1994 May;66(5):1678-93. doi: 10.1016/S0006-3495(94)80959-2. Biophys J. 1994. PMID: 8061216 Free PMC article.
MeSH terms
Substances
LinkOut - more resources
Medical
Miscellaneous