In this study we have used electrospray ionization mass spectrometry (ESI-MS) to investigate interactions between the bacterial K(+) channel KcsA and membrane phospholipids. KcsA was reconstituted into lipid vesicles of variable lipid composition. These vesicles were directly analyzed by ESI-MS or mixed with trifluoroethanol (TFE) before analysis. In the resulting mass spectra, non-covalent complexes of KcsA and phospholipids were observed with an interesting lipid specificity. The anionic phosphatidylglycerol (PG), and, to a lesser extent, the zwitterionic phosphatidylethanolamine (PE), which both are abundant bacterial lipids, were found to preferentially associate with KcsA as compared to the zwitterionic phosphatidylcholine (PC). These preferred interactions may reflect the differences in affinity of these phospholipids for KcsA in the membrane.
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http://dx.doi.org/10.1016/s0014-5793(03)00282-5 | DOI Listing |
ACS Nano
January 2025
Institute of Molecular Plus, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China.
Extracting lithium from salt lakes requires ion-selective membranes with customizable nanochannels. However, it remains a major challenge to separate alkali cations due to their same valences and similar ionic radius. Inspired by the K channel of KcsA K, significant progress has been made in adjusting nanochannel size to control the ion selectivity dominated by alkali cations dehydration.
View Article and Find Full Text PDFFaraday Discuss
October 2024
State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
Ion transport through biological channels is influenced not only by the structural properties of the channels themselves but also by the composition of the phospholipid membrane, which acts as a scaffold for these nanochannels. Drawing inspiration from how lipid membrane composition modulates ion currents, as seen in the activation of the K channel in Streptomyces A (KcsA) by anionic lipids, we propose a biomimetic nanochannel system that integrates DNA nanotechnology with two-dimensional graphene oxide (GO) nanosheets. By modifying the length of the multibranched DNA nanowires generated through the hybridization chain reaction (HCR) and varying the concentration of the linker strands that integrate these DNA nanowire structures with the GO membrane, the composition of the membrane can be effectively adjusted, consequently impacting ion transport.
View Article and Find Full Text PDFACS Nano
November 2024
Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan.
The biological membrane is not just a platform for information processing but also a field of mechanics. The lipid bilayer that constitutes the membrane is an elastic body, generating stress upon deformation, while the membrane protein embedded therein deforms the bilayer through structural changes. Among membrane-protein interplays, various channel species act as tension-current converters for signal transduction, serving as elementary processes in mechanobiology.
View Article and Find Full Text PDFNatl Sci Rev
August 2024
Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control for Aerospace Structures, Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Reproducing the outstanding selectivity achieved by biological ion channels in artificial channel systems can revolutionize applications ranging from membrane filtration to single-molecule sensing technologies, but achieving this goal remains a challenge. Herein, inspired by the selectivity filter structure of the KcsA potassium channel, we propose a design of biomimetic potassium nanochannels by functionalizing the wall of carbon nanotubes with an array of arranged carbonyl oxygen atoms. Our extensive molecular dynamics simulations show that the biomimetic nanochannel exhibits a high K permeation rate along with a high K/Na selectivity ratio.
View Article and Find Full Text PDFNatl Sci Rev
August 2024
School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, Australia.
Rechargeable aqueous Zn-ion batteries have been deemed a promising energy storage device. However, the dendrite growth and side reactions have hindered their practical application. Herein, inspired by the ultrafluidic and K ion-sieving flux through enzyme-gated potassium channels (KcsA) in biological plasma membranes, a metal-organic-framework (MOF-5) grafted with -ClO groups (MOF-ClO) as functional enzymes is fabricated to mimic the ultrafluidic lipid-bilayer structure for gating Zn 'on' and anions 'off' states.
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