Channels formed by amphotericin B covalent dimers exhibit rectification
Minako Hirano1, Yuko Takeuchi, Nobuaki Matsumori
1Laboratory for Cell Dynamics Observation, Planning Office for the Center for Computational and Quantitative Life Science, RIKEN, 7th Floor, Nanobiology Building, 1-3, Yamadaoka, Suita, Osaka 565-0871, Japan.
The Journal of Membrane Biology
|March 23, 2011
Summary
Amphotericin B (AmB) dimers form rectified ion channels in membranes, unlike some AmB monomers. This channel rectification depends on formation potential and offers a stable model for AmB channel structure.
Area of Science:
- Biophysics
- Mycology
- Membrane Biology
Background:
- Amphotericin B (AmB) is a crucial antifungal agent.
- Previous studies synthesized AmB dimers to understand its channel structure.
- An aminoalkyl linker AmB dimer showed significant hemolytic activity.
Purpose of the Study:
- To investigate the channel activity of AmB dimers.
- To compare rectification properties of AmB dimer and monomer channels.
- To propose a structural model for AmB channels.
Main Methods:
- Electrophysiological recordings of ion channels formed by AmB dimers and monomers.
- Varying electric potential during channel formation.
- Applying voltage stimulation to assess channel stability.
Main Results:
- All channels formed by AmB dimers exhibited rectification.
- Dimer channel rectification direction was dependent on formation electric potential.
- AmB monomer channels showed less consistent rectification, and dimer channels were more stable.
- Dimer channels demonstrated voltage-induced switching between rectified and non-rectified states.
Conclusions:
- AmB dimer channels consistently display rectification, influenced by membrane potential.
- A proposed model explains the inherent rectification of AmB dimer channels.
- These findings provide insights into Amphotericin B's mechanism of action.
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