A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes

Reynold Homan; Moisés Eisenberg

doi:10.1016/0005-2736(85)90323-2

A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes

Reynold Homan
, Moisés Eisenberg

Office of the Dean of Medicine

Stony Brook University

Research output: Contribution to journal › Article › peer-review

31 Scopus citations

Abstract

We have characterized the quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine by Co²⁺ in egg phosphatidylcholine (PC) lipid bilayer vesicles. The quenching constant obtained is 59 M^-1. We demonstrate one use of this fluorescence quenching technique by measuring intrinsic and X537A-mediated transmembrane Co²⁺ fluxes in large unilamellar PC vesicles. The intrinsic rate constant for Co²⁺ flux we measure is 3 · 10^-6s^-1. We confirm that the neutral Co ≈ (X537A)₂ complex is the main component of the X537A-mediated cobalt flux. Since this method measures the concentration of Co²⁺ at the site of the fluorophore, it is generally applicable to the measurement of paramagnetic ion concentrations in the region of the membrane/water interface.

Original language	English
Pages (from-to)	485-492
Number of pages	8
Journal	Biochimica et Biophysica Acta - Biomembranes
Volume	812
Issue number	2
DOIs	https://doi.org/10.1016/0005-2736(85)90323-2
State	Published - Jan 25 1985

Keywords

Co
Fluorescence quenching
Fluorescent probe
Ionophore X537A
Lipid vesicle
Membrane permeability
Membrane/water interface
Transmembrane flux

Access to Document

10.1016/0005-2736(85)90323-2

Cite this

@article{d04a3198e39740baaeb9d9d8e586ab53,

title = "A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes",

abstract = "We have characterized the quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine by Co2+ in egg phosphatidylcholine (PC) lipid bilayer vesicles. The quenching constant obtained is 59 M-1. We demonstrate one use of this fluorescence quenching technique by measuring intrinsic and X537A-mediated transmembrane Co2+ fluxes in large unilamellar PC vesicles. The intrinsic rate constant for Co2+ flux we measure is 3 · 10-6s-1. We confirm that the neutral Co ≈ (X537A)2 complex is the main component of the X537A-mediated cobalt flux. Since this method measures the concentration of Co2+ at the site of the fluorophore, it is generally applicable to the measurement of paramagnetic ion concentrations in the region of the membrane/water interface.",

keywords = "Co, Fluorescence quenching, Fluorescent probe, Ionophore X537A, Lipid vesicle, Membrane permeability, Membrane/water interface, Transmembrane flux",

author = "Reynold Homan and Mois{\'e}s Eisenberg",

year = "1985",

month = jan,

day = "25",

doi = "10.1016/0005-2736(85)90323-2",

language = "English",

volume = "812",

pages = "485--492",

journal = "Biochimica et Biophysica Acta - Biomembranes",

issn = "0005-2736",

number = "2",

}

A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes. / Homan, Reynold; Eisenberg, Moisés.
In: Biochimica et Biophysica Acta - Biomembranes, Vol. 812, No. 2, 25.01.1985, p. 485-492.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes

AU - Homan, Reynold

AU - Eisenberg, Moisés

PY - 1985/1/25

Y1 - 1985/1/25

N2 - We have characterized the quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine by Co2+ in egg phosphatidylcholine (PC) lipid bilayer vesicles. The quenching constant obtained is 59 M-1. We demonstrate one use of this fluorescence quenching technique by measuring intrinsic and X537A-mediated transmembrane Co2+ fluxes in large unilamellar PC vesicles. The intrinsic rate constant for Co2+ flux we measure is 3 · 10-6s-1. We confirm that the neutral Co ≈ (X537A)2 complex is the main component of the X537A-mediated cobalt flux. Since this method measures the concentration of Co2+ at the site of the fluorophore, it is generally applicable to the measurement of paramagnetic ion concentrations in the region of the membrane/water interface.

AB - We have characterized the quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine by Co2+ in egg phosphatidylcholine (PC) lipid bilayer vesicles. The quenching constant obtained is 59 M-1. We demonstrate one use of this fluorescence quenching technique by measuring intrinsic and X537A-mediated transmembrane Co2+ fluxes in large unilamellar PC vesicles. The intrinsic rate constant for Co2+ flux we measure is 3 · 10-6s-1. We confirm that the neutral Co ≈ (X537A)2 complex is the main component of the X537A-mediated cobalt flux. Since this method measures the concentration of Co2+ at the site of the fluorophore, it is generally applicable to the measurement of paramagnetic ion concentrations in the region of the membrane/water interface.

KW - Co

KW - Fluorescence quenching

KW - Fluorescent probe

KW - Ionophore X537A

KW - Lipid vesicle

KW - Membrane permeability

KW - Membrane/water interface

KW - Transmembrane flux

UR - https://www.scopus.com/pages/publications/0022431794

U2 - 10.1016/0005-2736(85)90323-2

DO - 10.1016/0005-2736(85)90323-2

M3 - Article

C2 - 2981549

AN - SCOPUS:0022431794

SN - 0005-2736

VL - 812

SP - 485

EP - 492

JO - Biochimica et Biophysica Acta - Biomembranes

JF - Biochimica et Biophysica Acta - Biomembranes

IS - 2

ER -

A fluorescence quenching technique for the measurement of paramagnetic ion concentrations at the membrane/water interface. Intrinsic and X537A-mediated cobalt fluxes across lipid bilayer membranes

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this