Analysis of a putative voltage-gated prokaryotic potassium channel

D. Ungar; A. Barth; W. Haase; A. Kaunzinger; E. Lewitzki; T. Ruiz; H. Reiländer; H. Michel

doi:10.1046/j.0014-2956.2001.02477.x

Analysis of a putative voltage-gated prokaryotic potassium channel

D. Ungar, A. Barth, W. Haase, A. Kaunzinger, E. Lewitzki, T. Ruiz, H. Reiländer, H. Michel

Biology

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

Abstract

Most of the completely sequenced prokaryotic genomes contain genes of potassium channel homologues, but there is still not much known about the role of these proteins in prokaryotes. Here we describe the large-scale overproduction and purification of a prokaryotic voltage-gated potassium channel homologue, Kch, from Escherichia coli. After successful overproduction of the protein, a specific increase in the potassium permeability of the cells was found. Kch could be purified in large amounts using classical purification methods to prevent aggregation of the protein. The physiological state of the protein was revealed to be a homotetramer and the protein was shown to be localized to the cytoplasmic membrane of the cells. In the course of the localization studies, we found a specific increase in the density of the cytoplasmic membrane on Kch production. This was linked to the observed increase in the protein to lipid ratio in the membranes. Another observed change in the membrane composition was an increase in the cardiolipin to phosphatidylglycerol ratio, which may indicate a specific cardiolipin requirement of Kch. On the basis of some of our results, we discuss a function for Kch in the maintenance of the membrane potential in E. coli.

Original language	English
Pages (from-to)	5386-5396
Number of pages	10
Journal	European Journal of Biochemistry
Volume	268
Issue number	20
DOIs	https://doi.org/10.1046/j.0014-2956.2001.02477.x
Publication status	Published - 2001

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10.1046/j.0014-2956.2001.02477.x

http://dx.doi.org/10.1046/j.0014-2956.2001.02477.x

Cite this

@article{00e0ba69e4ba4592945241e96fe53a70,

title = "Analysis of a putative voltage-gated prokaryotic potassium channel",

abstract = "Most of the completely sequenced prokaryotic genomes contain genes of potassium channel homologues, but there is still not much known about the role of these proteins in prokaryotes. Here we describe the large-scale overproduction and purification of a prokaryotic voltage-gated potassium channel homologue, Kch, from Escherichia coli. After successful overproduction of the protein, a specific increase in the potassium permeability of the cells was found. Kch could be purified in large amounts using classical purification methods to prevent aggregation of the protein. The physiological state of the protein was revealed to be a homotetramer and the protein was shown to be localized to the cytoplasmic membrane of the cells. In the course of the localization studies, we found a specific increase in the density of the cytoplasmic membrane on Kch production. This was linked to the observed increase in the protein to lipid ratio in the membranes. Another observed change in the membrane composition was an increase in the cardiolipin to phosphatidylglycerol ratio, which may indicate a specific cardiolipin requirement of Kch. On the basis of some of our results, we discuss a function for Kch in the maintenance of the membrane potential in E. coli.",

author = "D. Ungar and A. Barth and W. Haase and A. Kaunzinger and E. Lewitzki and T. Ruiz and H. Reil{\"a}nder and H. Michel",

year = "2001",

doi = "10.1046/j.0014-2956.2001.02477.x",

language = "English",

volume = "268",

pages = "5386--5396",

journal = "European Journal of Biochemistry",

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TY - JOUR

T1 - Analysis of a putative voltage-gated prokaryotic potassium channel

AU - Ungar, D.

AU - Barth, A.

AU - Haase, W.

AU - Kaunzinger, A.

AU - Lewitzki, E.

AU - Ruiz, T.

AU - Reiländer, H.

AU - Michel, H.

PY - 2001

Y1 - 2001

N2 - Most of the completely sequenced prokaryotic genomes contain genes of potassium channel homologues, but there is still not much known about the role of these proteins in prokaryotes. Here we describe the large-scale overproduction and purification of a prokaryotic voltage-gated potassium channel homologue, Kch, from Escherichia coli. After successful overproduction of the protein, a specific increase in the potassium permeability of the cells was found. Kch could be purified in large amounts using classical purification methods to prevent aggregation of the protein. The physiological state of the protein was revealed to be a homotetramer and the protein was shown to be localized to the cytoplasmic membrane of the cells. In the course of the localization studies, we found a specific increase in the density of the cytoplasmic membrane on Kch production. This was linked to the observed increase in the protein to lipid ratio in the membranes. Another observed change in the membrane composition was an increase in the cardiolipin to phosphatidylglycerol ratio, which may indicate a specific cardiolipin requirement of Kch. On the basis of some of our results, we discuss a function for Kch in the maintenance of the membrane potential in E. coli.

AB - Most of the completely sequenced prokaryotic genomes contain genes of potassium channel homologues, but there is still not much known about the role of these proteins in prokaryotes. Here we describe the large-scale overproduction and purification of a prokaryotic voltage-gated potassium channel homologue, Kch, from Escherichia coli. After successful overproduction of the protein, a specific increase in the potassium permeability of the cells was found. Kch could be purified in large amounts using classical purification methods to prevent aggregation of the protein. The physiological state of the protein was revealed to be a homotetramer and the protein was shown to be localized to the cytoplasmic membrane of the cells. In the course of the localization studies, we found a specific increase in the density of the cytoplasmic membrane on Kch production. This was linked to the observed increase in the protein to lipid ratio in the membranes. Another observed change in the membrane composition was an increase in the cardiolipin to phosphatidylglycerol ratio, which may indicate a specific cardiolipin requirement of Kch. On the basis of some of our results, we discuss a function for Kch in the maintenance of the membrane potential in E. coli.

U2 - 10.1046/j.0014-2956.2001.02477.x

DO - 10.1046/j.0014-2956.2001.02477.x

M3 - Article

SN - 0014-2956

VL - 268

SP - 5386

EP - 5396

JO - European Journal of Biochemistry

JF - European Journal of Biochemistry

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ER -