Identification of a voltage-responsive segment of the potential-gated colicin E1 ion channel
- 18 September 1990
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 29 (37), 8529-8534
- https://doi.org/10.1021/bi00489a004
Abstract
The voltage dependence of channel activity of the bactericidal protein colicin E1 was found to be correlated with insertion into the membrane bilayer of a specific segment of the 178-residue COOH-terminal thermolytic colicin channel peptide. The insertion into the bilayer was detected by an increase in labeling by one of two different lipophilic photoaffinity probes or by a decrease in iodination of peptide tyrosines from the external solution. Imposition of a potassium diffusion potential of -100 mV resulted in an increase of 35-60% in the labeling of the peptide by the lipophilic probe in the bilayer and a concomitant decrease in labeling of Tyr residues in the peptide by the iodination reagent in the external solution. The change in labeling decreased upon dissipation of the membrane potential with a half-time of about 1 min. The labeling change was localized to a 36-residue peptide segment bounded by alanine-425 and by tryptophan-460. This segment containing seven positively charged residues at low pH is a voltage-sensitive region that inserts into the membrane bilayer when the channel is turned on by the potential and is extruded from it when the voltage is removed and the channel is turned off.This publication has 20 references indexed in Scilit:
- On the nature of the structural change of the colicin E1 channel peptide necessary for its translocation-competent stateBiochemistry, 1990
- Dynamic properties of membrane proteins: reversible insertion into membrane vesicles of a colicin E1 channel-forming peptide.Proceedings of the National Academy of Sciences, 1988
- Voltage-dependent, monomeric channel activity of colicin E1 in artificial membrane vesiclesThe Journal of Membrane Biology, 1987
- Gating of a voltage-dependent channel (colicin E1) in planar lipid bilayers: translocation of regions outside the channel-forming domainThe Journal of Membrane Biology, 1986
- Channels formed by colicin E1 in planar lipid bilayers are large and exhibit pH-dependent ion selectivityThe Journal of Membrane Biology, 1985
- Nucleotide sequence of the structural gene for colicin E1 and predicted structure of the protein.Proceedings of the National Academy of Sciences, 1982
- Selective labeling of the hydrophobic core of membranes with 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine, a carbene-generating reagentBiochemistry, 1981
- Photogenerated reagents for membranes: selective labeling of intrinsic membrane proteins in the human erythrocyte membraneBiochemistry, 1980
- 5-[125I]Iodonaphthyl azide, a reagent to determine the penetration of proteins into the lipid bilayer of biological membranesBiochemistry, 1978
- Protein and cell membrane iodinations with a sparingly soluble chloroamide, 1,3,4,6-tetrachloro-3a,6a-diphenylglycolurilBiochemical and Biophysical Research Communications, 1978