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Polymer Induced Bundling of F-actin and the Depletion Force

M. Hosek·J. X. Tang
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Abstract

The inert polymer polyethylene glycol (PEG) induces a "bundling" phenomenon in F-actin solutions when its concentration exceeds a critical onset value C_o. Over a limited range of PEG molecular weight and ionic strength, C_o can be expressed as a function of these two variables. The process is reversible, but hysteresis is also observed in the dissolution of the bundles, with ionic strength having a large influence. Additional actin filaments are able to join previously formed bundles. Little, if any, polymer is associated with the bundle structure. Continuum estimates of the Asakura-Oosawa depletion force, Coulomb repulsion, and van der Waals potential are combined for a partial explanation of the bundling effect and hysteresis. Conjectures are presented concerning the apparent limit in bundle size.

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BibTeXRIS

M. Hosek, J. X. Tang. 2004-01-14. Polymer Induced Bundling of F-actin and the Depletion Force. https://doi.org/10.1103/physreve.69.051907

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