PMID:14581200

Citation	Lu, D, Grayson, P and Schulten, K (2003) Glycerol conductance and physical asymmetry of the Escherichia coli glycerol facilitator GlpF. Biophys. J. 85:2977-87
Abstract	The aquaglyceroporin GlpF is a transmembrane channel of Escherichia coli that facilitates the uptake of glycerol by the cell. Its high glycerol uptake rate is crucial for the cell to survive in very low glycerol concentrations. Although GlpF allows both influx and outflux of glycerol, its structure, similar to the structure of maltoporin, exhibits a significant degree of asymmetry. The potential of mean force characterizing glycerol in the channel shows a corresponding asymmetry with an attractive vestibule only at the periplasmic side. In this study, we analyze the potential of mean force, showing that a simplified six-step model captures the kinetics and yields a glycerol conduction rate that agrees well with observation. The vestibule improves the conduction rate by 40% and 75% at 10- micro M and 10-mM periplasmic glycerol concentrations, respectively. In addition, neither the conduction rate nor the conduction probability for a single glycerol (efficiency) depends on the orientation of GlpF. GlpF appears to conduct equally well in both directions under physiological conditions.
Links	PubMed PMC1303576 Online version:10.1016/S0006-3495(03)74718-3
Keywords	Aquaporins/chemistry; Computer Simulation; Diffusion; Escherichia coli Proteins/chemistry; Glycerol/chemistry; Ion Channel Gating; Models, Chemical; Models, Molecular; Motion; Porosity; Protein Conformation; Structure-Activity Relationship
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.