Direct visualization of flow-induced conformational transitions of single actin filaments in entangled solutions

I. Kirchenbuechler, D. Guu, N.A. Kurniawan, G. H. Koenderink, M.P. Lettinga

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)
120 Downloads (Pure)

Abstract

While semi-flexible polymers and fibres are an important class of material due to their rich mechanical properties, it remains unclear how these properties relate to the microscopic conformation of the polymers. Actin filaments constitute an ideal model polymer system due to their micron-sized length and relatively high stiffness that allow imaging at the single filament level. Here we study the effect of entanglements on the conformational dynamics of actin filaments in shear flow. We directly measure the full three-dimensional conformation of single actin filaments, using confocal microscopy in combination with a counter-rotating cone-plate shear cell. We show that initially entangled filaments form disentangled orientationally ordered hairpins, confined in the flow-vorticity plane. In addition, shear flow causes stretching and shear alignment of the hairpin tails, while the filament length distribution remains unchanged. These observations explain the strain-softening and shear-thinning behaviour of entangled F-actin solutions, which aids the understanding of the flow behaviour of complex fluids containing semi-flexible polymers.
Original languageEnglish
Article number5060
Pages (from-to)1-8
JournalNature Communications
Volume5
DOIs
Publication statusPublished - Oct 2014

Fingerprint

Dive into the research topics of 'Direct visualization of flow-induced conformational transitions of single actin filaments in entangled solutions'. Together they form a unique fingerprint.

Cite this