Non-Gaussian athermal fluctuations in active gels

Toshihiro Toyota, David A. Head, Christoph F. Schmidt, Daisuke Mizuno

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

Dynamic networks designed to model the cell cytoskeleton can be reconstituted from filamentous actin, the motor protein myosin and a permanent cross-linker. They are driven out of equilibrium when the molecular motors are active. This gives rise to athermal fluctuations that can be recorded by tracking probe particles that are dispersed in the network. We have here probed athermal fluctuations in such "active gels'' using video microrheology. We have measured the full distribution of probe displacements, also known as the van Hove correlation function. The dominant influence of thermal or athermal fluctuations can be detected by varying the lag time over which the displacements are measured. We argue that the exponential tails of the distribution derive from single motors close to the probes, and we extract an estimate of the velocity of motor heads along the actin filaments. The distribution exhibits a central Gaussian region which we assume derives from the action of many independent motor proteins far from the probe particles when athermal fluctuations dominate. Recording the whole distribution rather than just the typically measured second moment of probe fluctuations (mean-squared displacement) thus allowed us to differentiate between the effect of individual motors and the collective action of many motors.

Original languageEnglish
Pages (from-to)3234-3239
Number of pages6
JournalSoft Matter
Volume7
Issue number7
DOIs
Publication statusPublished - May 16 2011

Fingerprint

Gels
gels
probes
Actins
proteins
myosins
Myosins
trucks
filaments
Proteins
time lag
recording
moments
estimates
cells

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics

Cite this

Non-Gaussian athermal fluctuations in active gels. / Toyota, Toshihiro; Head, David A.; Schmidt, Christoph F.; Mizuno, Daisuke.

In: Soft Matter, Vol. 7, No. 7, 16.05.2011, p. 3234-3239.

Research output: Contribution to journalArticle

Toyota, T, Head, DA, Schmidt, CF & Mizuno, D 2011, 'Non-Gaussian athermal fluctuations in active gels', Soft Matter, vol. 7, no. 7, pp. 3234-3239. https://doi.org/10.1039/c0sm00925c
Toyota, Toshihiro ; Head, David A. ; Schmidt, Christoph F. ; Mizuno, Daisuke. / Non-Gaussian athermal fluctuations in active gels. In: Soft Matter. 2011 ; Vol. 7, No. 7. pp. 3234-3239.
@article{5ef25d9c431145afb6a7426ee1a6696b,
title = "Non-Gaussian athermal fluctuations in active gels",
abstract = "Dynamic networks designed to model the cell cytoskeleton can be reconstituted from filamentous actin, the motor protein myosin and a permanent cross-linker. They are driven out of equilibrium when the molecular motors are active. This gives rise to athermal fluctuations that can be recorded by tracking probe particles that are dispersed in the network. We have here probed athermal fluctuations in such {"}active gels'' using video microrheology. We have measured the full distribution of probe displacements, also known as the van Hove correlation function. The dominant influence of thermal or athermal fluctuations can be detected by varying the lag time over which the displacements are measured. We argue that the exponential tails of the distribution derive from single motors close to the probes, and we extract an estimate of the velocity of motor heads along the actin filaments. The distribution exhibits a central Gaussian region which we assume derives from the action of many independent motor proteins far from the probe particles when athermal fluctuations dominate. Recording the whole distribution rather than just the typically measured second moment of probe fluctuations (mean-squared displacement) thus allowed us to differentiate between the effect of individual motors and the collective action of many motors.",
author = "Toshihiro Toyota and Head, {David A.} and Schmidt, {Christoph F.} and Daisuke Mizuno",
year = "2011",
month = "5",
day = "16",
doi = "10.1039/c0sm00925c",
language = "English",
volume = "7",
pages = "3234--3239",
journal = "Soft Matter",
issn = "1744-683X",
publisher = "Royal Society of Chemistry",
number = "7",

}

TY - JOUR

T1 - Non-Gaussian athermal fluctuations in active gels

AU - Toyota, Toshihiro

AU - Head, David A.

AU - Schmidt, Christoph F.

AU - Mizuno, Daisuke

PY - 2011/5/16

Y1 - 2011/5/16

N2 - Dynamic networks designed to model the cell cytoskeleton can be reconstituted from filamentous actin, the motor protein myosin and a permanent cross-linker. They are driven out of equilibrium when the molecular motors are active. This gives rise to athermal fluctuations that can be recorded by tracking probe particles that are dispersed in the network. We have here probed athermal fluctuations in such "active gels'' using video microrheology. We have measured the full distribution of probe displacements, also known as the van Hove correlation function. The dominant influence of thermal or athermal fluctuations can be detected by varying the lag time over which the displacements are measured. We argue that the exponential tails of the distribution derive from single motors close to the probes, and we extract an estimate of the velocity of motor heads along the actin filaments. The distribution exhibits a central Gaussian region which we assume derives from the action of many independent motor proteins far from the probe particles when athermal fluctuations dominate. Recording the whole distribution rather than just the typically measured second moment of probe fluctuations (mean-squared displacement) thus allowed us to differentiate between the effect of individual motors and the collective action of many motors.

AB - Dynamic networks designed to model the cell cytoskeleton can be reconstituted from filamentous actin, the motor protein myosin and a permanent cross-linker. They are driven out of equilibrium when the molecular motors are active. This gives rise to athermal fluctuations that can be recorded by tracking probe particles that are dispersed in the network. We have here probed athermal fluctuations in such "active gels'' using video microrheology. We have measured the full distribution of probe displacements, also known as the van Hove correlation function. The dominant influence of thermal or athermal fluctuations can be detected by varying the lag time over which the displacements are measured. We argue that the exponential tails of the distribution derive from single motors close to the probes, and we extract an estimate of the velocity of motor heads along the actin filaments. The distribution exhibits a central Gaussian region which we assume derives from the action of many independent motor proteins far from the probe particles when athermal fluctuations dominate. Recording the whole distribution rather than just the typically measured second moment of probe fluctuations (mean-squared displacement) thus allowed us to differentiate between the effect of individual motors and the collective action of many motors.

UR - http://www.scopus.com/inward/record.url?scp=79955854221&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79955854221&partnerID=8YFLogxK

U2 - 10.1039/c0sm00925c

DO - 10.1039/c0sm00925c

M3 - Article

AN - SCOPUS:79955854221

VL - 7

SP - 3234

EP - 3239

JO - Soft Matter

JF - Soft Matter

SN - 1744-683X

IS - 7

ER -