Work

Condensation of isolated semi-flexible filaments driven by depletion interactions

Year: 2009

Type: article

Abstract: Using fluorescence microscopy, we directly visualize the condensed structures of individual semi-flexible actin filaments in a poor solvent. The condensation of filaments into either ring-like or racquet-like structures is driven by non-adsorbing polymers which induce attractive interactions between filaments via the well-known depletion mechanism. A quantitative analysis of the racquet structures yields a direct measurement of the adhesion strength between a pair of filaments. We also compare our experimental data with a theoretical model, demonstrating that in the limit of weak binding, thermal fluctuations can renormalize the effective strength of the attractive depletion interactions. Our experimental methods can be applied to other filamentous structures to directly measure their attractive intermolecular potentials.

Source: Europhysics Letters (EPL)

DOI: 10.1209/0295-5075/87/48006

Authors: A. W. C. Lau, A. Prasad, Z. Dogic

Institutions: Florida Atlantic University, Colorado State University, Harvard University, Rowland Institute at Harvard, Brandeis University

Language: English

Topic: Electrostatics and Colloid Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, Rowland Institute at Harvard, Materials Research Science and Engineering Center, Harvard University, Division of Materials Research

Awards: Constraints and Frustration in Nano-Structured and Bio-Molecular Materials, Chirality and Entropy in Self-Assembly of Biopolymers, Response and Fluctuations in Active Bacterial Suspensions