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Literature DB >> 2424023

Determination of the molecularity of the colicin E1 channel by stopped-flow ion flux kinetics.

Abstract

A fluorescence technique that measures fast ion fluxes across liposome membranes was used to determine the molecularity of the colicin E1 channel. The rate of flux of Tl+ (used as a K+ analogue) into large unilamellar vesicles was measured by its ability to quench the fluorescence of a membrane-impermeable fluorophore entrapped in the vesicles. The dependence of Tl+ flux rate on the concentration of ionophore in the vesicle suspension reveals the molecularity of the ionophore. The method is demonstrated with two ionophores, valinomycin and gramicidin, whose molecularities are known to be one and two, respectively. The molecularity of the colicin E1 channel was determined to be one. This method can be used to study the properties of any ionophore that mediates K+ flux.

Entities: Chemical

Mesh：

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Year: 1986 PMID： 2424023 PMCID： PMC323714 DOI： 10.1073/pnas.83.12.4273

Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205

20 in total

1. Phosphorus assay in column chromatography.

Authors: G R BARTLETT
Journal: J Biol Chem Date: 1959-03 Impact factor: 5.157

2. THE ADSORPTION AND KINETICS OF KILLING BY COLICIN CA42-E2.

Authors: P REEVES
Journal: Aust J Exp Biol Med Sci Date: 1965-04

3. Channels formed by colicin E1 in planar lipid bilayers are large and exhibit pH-dependent ion selectivity.

Authors: L Raymond; S L Slatin; A Finkelstein
Journal: J Membr Biol Date: 1985 Impact factor: 1.843

4. Kinetics of adsorption of colicin CA42-E2 and reversal of its bactericidal activity.

Authors: B L Reynolds; P R Reeves
Journal: J Bacteriol Date: 1969-10 Impact factor: 3.490

Review 5. Colicins and other bacteriocins with established modes of action.

Authors: J Konisky
Journal: Annu Rev Microbiol Date: 1982 Impact factor: 15.500

Review 6. The membrane channel-forming bacteriocidal protein, colicin El.

Authors: W A Cramer; J R Dankert; Y Uratani
Journal: Biochim Biophys Acta Date: 1983-03-21

7. Direct spectroscopic studies of cation translocation by Torpedo acetylcholine receptor on a time scale of physiological relevance.

Authors: H P Moore; M A Raftery
Journal: Proc Natl Acad Sci U S A Date: 1980-08 Impact factor: 11.205

8. Colicin K acts by forming voltage-dependent channels in phospholipid bilayer membranes.

Authors: S J Schein; B L Kagan; A Finkelstein
Journal: Nature Date: 1978-11-09 Impact factor: 49.962

9. Simultaneous fluorescence and conductance studies of planar bilayer membranes containing a highly active and fluorescent analog of gramicidin A.

Authors: W R Veatch; R Mathies; M Eisenberg; L Stryer
Journal: J Mol Biol Date: 1975-11-25 Impact factor: 5.469

10. Is the gramicidin a transmembrane channel single-stranded or double-stranded helix? A simple unequivocal determination.

Authors: D W Urry; T L Trapane; K U Prasad
Journal: Science Date: 1983-09-09 Impact factor: 47.728

10 in total

1. Colicin E1 forms a dimer after urea-induced unfolding.

Authors: B A Steer; A A DiNardo; A R Merrill
Journal: Biochem J Date: 1999-06-15 Impact factor: 3.857

2. Gramicidin-based fluorescence assay; for determining small molecules potential for modifying lipid bilayer properties.

Authors: Helgi I Ingólfsson; R Lea Sanford; Ruchi Kapoor; Olaf S Andersen
Journal: J Vis Exp Date: 2010-10-13 Impact factor: 1.355

Determination of the molecularity of the colicin E1 channel by stopped-flow ion flux kinetics.

1. Phosphorus assay in column chromatography.

2. THE ADSORPTION AND KINETICS OF KILLING BY COLICIN CA42-E2.

3. Channels formed by colicin E1 in planar lipid bilayers are large and exhibit pH-dependent ion selectivity.

4. Kinetics of adsorption of colicin CA42-E2 and reversal of its bactericidal activity.

Review 5. Colicins and other bacteriocins with established modes of action.

Review 6. The membrane channel-forming bacteriocidal protein, colicin El.

7. Direct spectroscopic studies of cation translocation by Torpedo acetylcholine receptor on a time scale of physiological relevance.

8. Colicin K acts by forming voltage-dependent channels in phospholipid bilayer membranes.

9. Simultaneous fluorescence and conductance studies of planar bilayer membranes containing a highly active and fluorescent analog of gramicidin A.

10. Is the gramicidin a transmembrane channel single-stranded or double-stranded helix? A simple unequivocal determination.

1. Colicin E1 forms a dimer after urea-induced unfolding.

2. Gramicidin-based fluorescence assay; for determining small molecules potential for modifying lipid bilayer properties.

3. Voltage-dependent conductance for alamethicin in phospholipid vesicles. A test for the mechanism of gating.

4. Small-molecule photostabilizing agents are modifiers of lipid bilayer properties.

5. In vivo properties of colicin A: channel activity is voltage dependent but translocation may be voltage independent.

6. Voltage-dependent, monomeric channel activity of colicin E1 in artificial membrane vesicles.

Review 7. Interaction of mitochondrial porin with cytosolic proteins.

8. Screening for small molecules' bilayer-modifying potential using a gramicidin-based fluorescence assay.

9. Exchange of Gramicidin between Lipid Bilayers: Implications for the Mechanism of Channel Formation.

10. Major transmembrane movement associated with colicin Ia channel gating.