Abstract

The assembly of actin filaments into bundles plays an essential role in mechanical strength and dynamic reorganization of cytoskeleton. Divalent counterions at high concentrations promote bundle formation through electrostatic attraction between charged filaments. Although it has been hypothesized that specific cation interactions may contribute to salt-induced bundling, molecular mechanisms of how salt modulates bundle assembly and mechanics are not well established. Here we determine the mechanical and dynamic properties of actin bundles with physiologically relevant cations. Using total internal reflection fluorescence (TIRF) microscopy, we measure the bending stiffness of actin bundles determined by persistence length analysis. We characterize real-time formation of bundles by dynamic light scattering intensity and direct visualization using TIRF microscopy. Our results show that divalent cations modulate bundle stiffness as well as time-dependent average bundle size. Furthermore, molecular dynamic simulations propose specificity for cation binding on actin filaments to form bundles. The work suggests that cation interactions serve a regulatory function in bundle assembly dynamics, mechanics, and structure.

Graduation Date

2017

Semester

Spring

Advisor

Kang, Hyeran

Degree

Master of Science (M.S.)

College

College of Graduate Studies

Department

Nanoscience Technology Center

Degree Program

Nanotechnology

Format

application/pdf

Identifier

CFE0006572

URL

http://purl.fcla.edu/fcla/etd/CFE0006572

Language

English

Release Date

May 2018

Length of Campus-only Access

1 year

Access Status

Masters Thesis (Campus-only Access)

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