+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Role of the potential landscape on the single-file diffusion through channels



Role of the potential landscape on the single-file diffusion through channels



Journal of Chemical Physics 141(22): 224901



Transport of colloid particles through narrow channels is ubiquitous in cell biology as well as becoming increasingly important for microfluidic applications or targeted drug delivery. Membrane channels in cells are useful models for artificial designs because of their high efficiency, selectivity, and robustness to external fluctuations. Here, we model the passive channels that let cargo simply diffuse through them, affected by a potential profile along the way. Passive transporters achieve high levels of efficiency and specificity from binding interactions with the cargo inside the channel. This however leads to a paradox: why should channels which are so narrow that they are blocked by their cargo evolve to have binding regions for their cargo if that will effectively block them? Using Brownian dynamics simulations, we show that different potentials, notably symmetric, increase the flux through narrow passive channels - and investigate how shape and depth of potentials influence the flux. We find that there exist optimal depths for certain potential shapes and that it is most efficient to apply a small force over an extended region of the channel. On the other hand, having several spatially discrete binding pockets will not alter the flux significantly. We also explore the role of many-particle effects arising from pairwise particle interactions with their neighbours and demonstrate that the relative changes in flux can be accounted for by the kinetics of the absorption reaction at the end of the channel.

(PDF emailed within 0-6 h: $19.90)

Accession: 058791455

Download citation: RISBibTeXText

PMID: 25494767

DOI: 10.1063/1.4903175


Related references

Single-file diffusion of colloids in one-dimensional channels. Science 287(5453): 5-7, 2000

Single-file diffusion of colloids in one-dimensional channels. Physical Review Letters 93(2): 026001, 2004

Single-file diffusion through K+ channels in frog skin epithelium. Journal of Membrane Biology 91(3): 245-250, 1986

Single-file and normal diffusion of magnetic colloids in modulated channels. Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics 89(3): 032306, 2014

Single-file diffusion multi-ion mechanism of permeation in paracellular epithelial channels. Journal of Membrane Biology 64(1-2): 103-112, 1982

Single-file diffusion in periodic energy landscapes: the role of hydrodynamic interactions. Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics 86(3 Pt 1): 031123, 2012

Single-particle tracking of membrane protein diffusion in a potential: simulation, detection, and application to confined diffusion of CFTR Cl- channels. Biophysical Journal 93(3): 1079-1088, 2007

Nature of the modification of the surface of potential energy in the reactions of the formation and destruction of the ion triads carbaxyl ion sodium ion and the problems of single file cationic diffusion in biochannels. Doklady Akademii Nauk SSSR 311(1): 228-231, 1990

Transverse single-file diffusion and enhanced longitudinal diffusion near a subcritical bifurcation. Physical Review. E 97(5-1): 052134, 2018

Relationship between single-file diffusion of mixed and pure gases in dipeptide nanochannels by high field diffusion NMR. Chemical Communications 51(69): 13346-9, 2015

From single-file diffusion to two-dimensional cage diffusion and generalization of the totally asymmetric simple exclusion process to higher dimensions. Physical Review. E 93(1): 012134, 2016

Transition from single-file to Fickian diffusion for binary mixtures in single-walled carbon nanotubes. Journal of Chemical Physics 133(9): 094501, 2010

Single file diffusion. Biomembranes 3: 127-153, 1972

Single-file diffusion in a box. Physical Review Letters 100(20): 200601, 2008

Observation of single-file diffusion in a MOF. Physical Chemistry Chemical Physics 18(26): 17190-5, 2016