Transients of perforin pore formation observed by fluorescence microscopic single channel recording

Détails

ID Serval
serval:BIB_DD9CAA77F716
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Transients of perforin pore formation observed by fluorescence microscopic single channel recording
Périodique
EMBO Journal
Auteur⸱e⸱s
Peters  R., Sauer  H., Tschopp  J., Fritzsch  G.
ISSN
0261-4189 (Print)
Statut éditorial
Publié
Date de publication
08/1990
Volume
9
Numéro
8
Pages
2447-2451
Notes
Journal Article Research Support, Non-U.S. Gov't --- Old month value: Aug
Résumé
A new type of single channel recording is described. Large pores were generated in the membranes of resealed human erythrocyte ghosts by incubation with perforin (cytolysin). The flux of the polar fluorescent probe Lucifer Yellow was measured in single ghosts by the fluorescence microphotolysis (photobleaching) technique. The distribution of flux rates for ghosts treated with a limiting perforin concentration showed equidistantly spaced peaks suggesting that subpopulations of ghosts with 0, 1 and 2 pores were resolved. Furthermore, distributions obtained for very different perforin concentrations could be well simulated by using one common value for the flux rate of the single pore (k = 4.65 x 10(-3) s) and assuming a Poisson distribution of pores among ghosts. The flux rate of the single pore corresponds to a pore radius of approximately 50 A, a value which is much smaller than that obtained previously by electron microscopic studies but which agrees well with recent electrical single channel recordings. Mature perforin pores were observed to be very stable. No closing events were detected at a time resolution of 0.2 s for a wide range of temperatures and Ca2+ concentrations. However, the formation of new pores was an unexpectedly slow process. Fluorescence microscopic single channel recording as introduced by this study is applicable to a variety of cellular systems and fluorescent probes and thus may complement the information obtainable by electrical single channel recording of anorganic ion fluxes.
Mots-clé
Erythrocyte Membrane/drug effects/*physiology/ultrastructure Humans Ion Channels/*physiology Kinetics *Membrane Glycoproteins Membrane Proteins/*pharmacology Microscopy, Fluorescence/methods Photolysis Pore Forming Cytotoxic Proteins T-Lymphocytes, Cytotoxic
Pubmed
Web of science
Création de la notice
24/01/2008 16:19
Dernière modification de la notice
20/08/2019 17:02
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