Translocation of small molecules through engineered outer-membrane channels from Gram-negative bacteria
Rémi Terrasse1, Mathias Winterhalter2
1Department of Life Sciences and Chemistry, Jacobs University Bremen, D-28719, Bremen, Germany.
The European Physical Journal. E, Soft Matter
|September 22, 2018
Summary
Researchers developed a new method using artificial amino acids to track small molecules passing through bacterial porin channels. This technique successfully detected molecules within the porin, enabling future quantification of translocation.
Area of Science:
- Biochemistry
- Molecular Biology
- Membrane Biophysics
Background:
- Biological membranes exhibit selective permeability, regulated by lipid bilayers and channel proteins.
- Porins, channel proteins in Gram-negative bacteria, control the passage of small molecules.
- Understanding porin transport is crucial for drug delivery and antibiotic resistance studies.
Purpose of the Study:
- To introduce a novel method for studying small molecule permeation through bacterial porins.
- To utilize artificial amino acids and Förster Resonance Energy Transfer (FRET) to monitor molecule dynamics within porins.
- To establish a foundation for quantifying molecular translocation through porins.
Main Methods:
- Incorporation of a fluorescent artificial amino acid (Hco) into the OmpF porin.
- Measurement of FRET between Hco and a fluorescently labeled small molecule (Bocillin FL).
- Analysis of FRET signals from solubilized OmpF porin variants.
Main Results:
- Demonstrated that small molecules, such as Bocillin FL, reside within the OmpF porin long enough for FRET to occur.
- Generated reproducible fluorescence signals, confirming the feasibility of the FRET-based approach.
- Showcased the potential of using Hco-labeled porins to study molecular interactions and transport.
Conclusions:
- The developed method using artificial amino acids and FRET provides a sensitive way to study porin transport.
- This approach allows for the detection and potential quantification of small molecule translocation events.
- Future applications include simultaneous detection of resistive pulses and differential fluorescence for comprehensive translocation analysis.
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