Cations Modulate Actin Bundle Mechanics, Assembly Dynamics, and Structure

被引：24

作者：

Castaneda, Nicholas ^{[1
,2
]}

Zheng, Tianyu ^{[1
,3
]}

Rivera-Jacquez, Hector J. ^{[1
]}

Lee, Hyun-Ju ^{[5
]}

Hyun, Jaekyung ^{[5
]}

Balaeff, Alexander ^{[1
,4
]}

Huo, Qun ^{[1
,3
]}

Kang, Hyeran ^{[1
,4
]}

机构：

[1] Univ Cent Florida, NanoSci Technol Ctr, Orlando, FL 32826 USA

[2] Univ Cent Florida, Coll Med, Burnett Sch Biomed Sci, Orlando, FL 32827 USA

[3] Univ Cent Florida, Dept Chem, Orlando, FL 32816 USA

[4] Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA

[5] Korea Basic Sci Inst KBSI, Electron Microscopy Res Ctr, Cheongju 28119, Chungcheongbuk, South Korea

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2018年 / 122卷 / 14期

关键词：

F-ACTIN; POLYELECTROLYTE SOLUTIONS; COUNTERION CONDENSATION; MOLECULAR-DYNAMICS; BENDING STIFFNESS; CHARGE-DENSITY; FASCIN; PROTEINS; COFILIN; BINDING;

D O I：

10.1021/acs.jpcb.8b00663

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Actin bundles are key factors in the mechanical support and dynamic reorganization of the cytoskeleton. High concentrations of multivalent counterions promote bundle formation through electrostatic attraction between actin filaments that are negatively charged polyelectrolytes. In this study, we evaluate how physiologically relevant divalent cations affect the mechanical, dynamic, and structural properties of actin bundles. Using a combination of total internal reflection fluorescence microscopy, transmission electron microscopy, and dynamic light scattering, we demonstrate that divalent cations modulate bundle stiffness, length distribution, and lateral growth. Molecular dynamics simulations of an all-atom model of the actin bundle reveal specific actin residues coordinate cation-binding sites that promote the bundle formation. Our work suggests that specific cation interactions may play a fundamental role in the assembly, structure, and mechanical properties of actin bundles.

引用

页码：3826 / 3835

页数：10

共 46 条

[1] Structure and dynamics of condensed multivalent ions within polyelectrolyte bundles: a combined x-ray diffraction and solid-state NMR study [J].