PMID:15600440
| Citation |
Levadny, V, Aguilella, VM, Aguilella-Arzo, M and Belaya, M (2004) Interaction of a polar molecule with an ion channel. Phys Rev E Stat Nonlin Soft Matter Phys 70:041912 |
|---|---|
| Abstract |
The binding of a polar macromolecule to a large ion channel is studied theoretically, paying special attention to the influence of external conditions (applied voltage and ion strength of solution). The molecule behavior in bound state is considered as random thermal fluctuations within a limited fraction of its phase space. The mean duration of molecule binding (residence time tau r) is represented as the mean first passage time to reach the boundary of that restricted domain. By invoking the adiabatic approximation we reduce the problem to one dimension with the angle between macromolecule dipole and channel axes being the key variable of the problem. The model accounts for experimental measurements of tau r for the antibiotic Ampicillin within the bacterial porin OmpF of Escherichia coli. By assuming that the electrical interaction between Ampicillin dipole and OmpF ionizable groups affects the fluctuations, we find that the biased residence time-voltage dependence observed in experiments is the result of the strong transversal electric field in OmpF constriction with a tilt approximately 30 degrees aside the cis side. |
| Links | |
| Keywords |
Ampicillin/chemistry; Ampicillin/metabolism; Binding Sites; Computer Simulation; Electrochemistry/methods; Escherichia coli Proteins/chemistry; Escherichia coli Proteins/metabolism; Ion Channel Gating/physiology; Kinetics; Membrane Potentials/physiology; Models, Biological; Models, Chemical; Porins/chemistry; Porins/metabolism; Protein Binding; Static Electricity |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.