Non-Gaussian subdiffusion of single-molecule tracers in a hydrated polymer network
Open Access
- 8 January 2020
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 152 (2), 024903
- https://doi.org/10.1063/1.5128743
Abstract
Single molecule tracking experiments inside a hydrated polymer network have shown that the tracer motion is subdiffusive due to the viscoelastic environment inside the gel-like network. This property can be related to the negative autocorrelation of the instantaneous displacements at short times. Although the displacements of the individual tracers exhibit Gaussian statistics, the displacement distribution of all the trajectories combined from different spatial locations of the polymer network exhibits a non-Gaussian distribution. Here, we analyze many individual tracer trajectories to show that the central portion of the non-Gaussian distribution can be well approximated by an exponential distribution that spreads sublinearly with time. We explain all these features seen in the experiment by a generalized Langevin model for an overdamped particle with algebraically decaying correlations. We show that the degree of non-Gaussianity can change with the extent of heterogeneity, which is controlled in our model by the experimentally observed distributions of the motion parameters.Funding Information
- Science and Engineering Research Board (ECR/2016/001967)
This publication has 80 references indexed in Scilit:
- Single-Molecule Kinetics in Living CellsAnnual Review of Biochemistry, 2019
- Single-Molecule Fluorescence Microscopy Reveals Local Diffusion Coefficients in the Pore Network of an Individual Catalyst ParticleJournal of the American Chemical Society, 2017
- Non-Brownian diffusion in lipid membranes: Experiments and simulationsBiochimica et Biophysica Acta (BBA) - Biomembranes, 2016
- Testing Landscape Theory for Biomolecular Processes with Single Molecule Fluorescence SpectroscopyPhysical Review Letters, 2015
- Probing the type of anomalous diffusion with single-particle trackingPhysical Chemistry Chemical Physics, 2014
- Anomalous transport in the crowded world of biological cellsReports on Progress in Physics, 2013
- Bacterial Chromosomal Loci Move Subdiffusively through a Viscoelastic CytoplasmPhysical Review Letters, 2010
- Single-molecule experiments in biological physics: methods and applicationsJournal of Physics: Condensed Matter, 2006
- Physical Nature of Bacterial CytoplasmPhysical Review Letters, 2006
- Fokker-Planck EquationPublished by Springer Science and Business Media LLC ,1996