title: Biophysical characterization of cofilin-induced extension-torsion coupling in actin filaments.
abstract: Cofilin makes the actin filament flexible and thermally unstable by disassembling the filament and inducing bending and torsional compliance. Actin monomers bound to cofilin are able to chemically and mechanically interact in response to external forces. In this study, we performed two molecular dynamics tensile tests for actin and cofilactin filaments under identical conditions. Surprisingly, cofilactin filaments were found to be twisted, generating shear stress caused by torsion. Additionally, analysis by plane stress assumption indicated that the extension-torsion coupling effect increases the amount of principal stress by 10%. Using elasticity and solid mechanics theories, our study elucidates the role of cofilin in the disassembly of actin filaments under tensile forces.
authors.affiliation: Department of Mechanical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Jae In
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Department of Mechanical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Junpyo
authors.initials: J
authors.lastname: Kwon
authors.affiliation: Department of Mechanical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Inchul
authors.initials: I
authors.lastname: Baek
authors.affiliation: Department of Mechanical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea. Electronic address: nass@korea.ac.kr.
authors.forename: Sungsoo
authors.initials: S
authors.lastname: Na
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology*; D051339:Actin Depolymerizing Factors / Q000502:physiology*; D055592:Biophysical Phenomena; D004548:Elasticity; D056004:Molecular Dynamics Simulation; D013314:Stress, Mechanical
chemical_list: D051339:Actin Depolymerizing Factors
keywords: Actin; Cofilin; Coupling effect; Extension; SMD; Torsion