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Tandem Gramicidin Channels Cross-linked by Streptavidin
The interaction of biotin-binding proteins with biotinylated gramicidin (gA5XB) was studied by monitoring single-channel activity and sensitized photoinactivation kinetics. It was discovered that the addition of streptavidin or avidin to the bathing solutions of a bilayer lipid membrane (BLM) with i...
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
2003
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217381/ https://www.ncbi.nlm.nih.gov/pubmed/12719486 http://dx.doi.org/10.1085/jgp.200208780 |
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author | Rokitskaya, Tatyana I. Kotova, Elena A. Antonenko, Yuri N. |
author_facet | Rokitskaya, Tatyana I. Kotova, Elena A. Antonenko, Yuri N. |
author_sort | Rokitskaya, Tatyana I. |
collection | PubMed |
description | The interaction of biotin-binding proteins with biotinylated gramicidin (gA5XB) was studied by monitoring single-channel activity and sensitized photoinactivation kinetics. It was discovered that the addition of streptavidin or avidin to the bathing solutions of a bilayer lipid membrane (BLM) with incorporated gA5XB induced the opening of a channel characterized by approximately doubled single-channel conductance and extremely long open-state duration. We believe that the deceleration of the photoinactivation kinetics observed here with streptavidin and previously (Rokitskaya, T.I., Y.N. Antonenko, E.A. Kotova, A. Anastasiadis, and F. Separovic. 2000. Biochemistry. 39:13053–13058) with avidin reflects the formation of long-lived channels of this type. Both opening and closing of the double-conductance channels occurred via a transient sub-state of the conductance coinciding with that of the usual single-channel transition. The appearance of the double-conductance channels after the addition of streptavidin was preceded by bursts of fast fluctuations of the current with the open state duration of the individual events of 60 ms. The streptavidin-induced double-conductance channels appeared to be inherent only to the gramicidin analogue with a biotin group linked to the COOH terminus through a long linker arm. Including biotinylated phosphatidylethanolamine into the BLM prevented the formation of the double-conductance channels even with the excess streptavidin. In view of the results obtained here, it is suggested that the double-conductance channel represents a tandem of two neighboring gA5XB channels with their COOH termini being cross-linked by the bound streptavidin at both sides of the BLM. The finding that streptavidin induces the formation of the tandem gramicidin channel comprising two channels functioning in concert is considered to be relevant to the physiologically important phenomenon of ligand-induced receptor oligomerization. |
format | Text |
id | pubmed-2217381 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2003 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22173812008-04-16 Tandem Gramicidin Channels Cross-linked by Streptavidin Rokitskaya, Tatyana I. Kotova, Elena A. Antonenko, Yuri N. J Gen Physiol Article The interaction of biotin-binding proteins with biotinylated gramicidin (gA5XB) was studied by monitoring single-channel activity and sensitized photoinactivation kinetics. It was discovered that the addition of streptavidin or avidin to the bathing solutions of a bilayer lipid membrane (BLM) with incorporated gA5XB induced the opening of a channel characterized by approximately doubled single-channel conductance and extremely long open-state duration. We believe that the deceleration of the photoinactivation kinetics observed here with streptavidin and previously (Rokitskaya, T.I., Y.N. Antonenko, E.A. Kotova, A. Anastasiadis, and F. Separovic. 2000. Biochemistry. 39:13053–13058) with avidin reflects the formation of long-lived channels of this type. Both opening and closing of the double-conductance channels occurred via a transient sub-state of the conductance coinciding with that of the usual single-channel transition. The appearance of the double-conductance channels after the addition of streptavidin was preceded by bursts of fast fluctuations of the current with the open state duration of the individual events of 60 ms. The streptavidin-induced double-conductance channels appeared to be inherent only to the gramicidin analogue with a biotin group linked to the COOH terminus through a long linker arm. Including biotinylated phosphatidylethanolamine into the BLM prevented the formation of the double-conductance channels even with the excess streptavidin. In view of the results obtained here, it is suggested that the double-conductance channel represents a tandem of two neighboring gA5XB channels with their COOH termini being cross-linked by the bound streptavidin at both sides of the BLM. The finding that streptavidin induces the formation of the tandem gramicidin channel comprising two channels functioning in concert is considered to be relevant to the physiologically important phenomenon of ligand-induced receptor oligomerization. The Rockefeller University Press 2003-05 /pmc/articles/PMC2217381/ /pubmed/12719486 http://dx.doi.org/10.1085/jgp.200208780 Text en Copyright © 2003, The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Rokitskaya, Tatyana I. Kotova, Elena A. Antonenko, Yuri N. Tandem Gramicidin Channels Cross-linked by Streptavidin |
title | Tandem Gramicidin Channels Cross-linked by Streptavidin |
title_full | Tandem Gramicidin Channels Cross-linked by Streptavidin |
title_fullStr | Tandem Gramicidin Channels Cross-linked by Streptavidin |
title_full_unstemmed | Tandem Gramicidin Channels Cross-linked by Streptavidin |
title_short | Tandem Gramicidin Channels Cross-linked by Streptavidin |
title_sort | tandem gramicidin channels cross-linked by streptavidin |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217381/ https://www.ncbi.nlm.nih.gov/pubmed/12719486 http://dx.doi.org/10.1085/jgp.200208780 |
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