Antibiotic translocation through membrane channels: temperature-dependent ion current fluctuation for catching the
Kozhinjampara R Mahendran1, Catalin Chimerel, Tivadar Mach
1School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, Bremen, Germany.
Abstract:
Temperature-dependent facilitated permeation of antibiotics through membrane channels was investigated. Here we reconstituted single OmpF trimers from the outer membrane of Escherichia coli (E. coli) into a planar lipid bilayer. The penetration of ampicillin through OmpF causes fluctuation in the ion current, and analysis of the fluctuations at different temperatures allows us to determine the mode of permeation. The residence time of the drug inside the channel decays strongly with temperature, reaching the resolution limit of the instrument at 30 degrees C. The number of events increases exponentially with temperature up to 30 degrees C and then gradually decreases as temperature increases. At room temperature, we observe about 25 events per second per monomer of the trimeric channel and an extrapolation to 37 degrees C gives roughly 50 events. The activation energy for ampicillin translocation through OmpF is estimated to be around 13 kT. Temperature-dependent study gives new insights into the faster translocation of small substrates through biological nanopores.
More Related Videos
11:51Application of Electrophysiology Measurement to Study the Activity of Electro-Neutral Transporters
Published on: February 3, 2018
08:55Single-Molecule Imaging of Lateral Mobility and Ion Channel Activity in Lipid Bilayers using Total Internal Reflection Fluorescence (TIRF) Microscopy
Published on: February 17, 2023
Related Concept Videos
Ion Channels
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
Protein Diffusion in the Membrane
Drug Absorption Mechanism: Passive Membrane Transport
Drug Absorption Mechanism: Carrier-Mediated Membrane Transport
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
Pore Transport and Ion-Pair Transport
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Facilitated Diffusion
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
