Divalent cation-sensitive pores formed by natural and synthetic melittin and by Triton X-100
| Autor: | W.M. Arnold, C. L. Bashford, G. M. Alder, Alex F. Drake, U. Zimmermann, Charles A. Pasternak |
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| Rok vydání: | 1991 |
| Předmět: |
Circular dichroism
Cell Membrane Permeability Cations Divalent Octoxynol Detergents Biophysics Centrifugation complex mixtures Biochemistry Melittin Polyethylene Glycols Divalent Mice chemistry.chemical_compound Animals Lipid bilayer Egtazic Acid Cells Cultured Fluorescent Dyes chemistry.chemical_classification Liposome Chromatography Circular Dichroism technology industry and agriculture Cell Biology Melitten Calcein Kinetics Zinc EGTA Energy Transfer chemistry Liposomes Triton X-100 Calcium lipids (amino acids peptides and proteins) Stearic Acids |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1061:111-120 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/0005-2736(91)90275-d |
| Popis: | Leakage of ions and low-molecular-weight metabolites from Lettre cells is induced by synthetic melittin, as effectively as by melittin isolated from bee venom; in each case leakage is inhibited by Ca 2+ , Zn 2+ or H + . Inhibition of leakage by divalent cations is reversible in that Lettre cells incubated with melittin (or with Triton X-100) in the presence of inhibitory amounts of Zn 2+ , when freed of Zn 2+ by EGTA or by centrifugation, begin to leak (in Zn 2+ -sensitive manner). Electrorotation of Lettre cells is altered by melittin, compatible with membrane permeabilization; melittin plus Zn 2+ does not alter electrorotation until Zn 2+ (and unbound melittin) are removed. Melittin or Triton X-100 added to calcein-loaded liposomes induces leakage of calcein; divalent cations inhibit. Energy transfer between liposome-associated melittin and 2-, 7- or 12-(9-anthroyloxy)stearate (AS) is maximal with 12-AS: addition of Zn 2+ has little effect. Circular dichroism spectra of melittin plus liposomes are unaffected by Zn 2+ . These results show that the formation of divalent cation-sensitive pores is not dependent on the presence of endogenous membrane proteins and that the action of divalent cations is not by displacement of melittin (or Triton) from the lipid bilayer. |
| Databáze: | OpenAIRE |
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