Active, motor-driven mechanics in a DNA gel

Cells are capable of a variety of dramatic stimuli-responsive mechanical behaviors. These capabilities are enabled by the pervading cytoskeletal network, an active gel composed of structural filaments (e.g., actin) that are acted upon by motor proteins (e.g., myosin). Here, we describe the synthesis...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2012-10, Vol.109 (43), p.17342-17347
Main Authors: Bertrand, Olivier J. N., Fygenson, Deborah Kuchnir, Saleh, Omar A.
Format: Article
Language:English
Subjects:
Actins
Biological Sciences
Biomechanical Phenomena
Cells
Cytoskeleton
Deoxyribonucleic acid
DNA
DNA - chemistry
Fracture mechanics
Gels
Measurement
Molecular Motor Proteins - chemistry
Motors
Nanotubes
Physical Sciences
Proteins
Self assembly
Stiffness
Trajectories
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Summary:Cells are capable of a variety of dramatic stimuli-responsive mechanical behaviors. These capabilities are enabled by the pervading cytoskeletal network, an active gel composed of structural filaments (e.g., actin) that are acted upon by motor proteins (e.g., myosin). Here, we describe the synthesis and characterization of an active gel using noncytoskeletal components. We use methods of base-pair-templated DNA self assembly to create a hybrid DNA gel containing stiff tubes and flexible linkers. We then activate the gel by adding the motor FtsK50C, a construct derived from the bacterial protein FtsK that, in vitro, has a strong and processive DNA contraction activity. The motors stiffen the get and create stochastic contractile events that affect the positions of attached beads. We quantify the fluctuations of the beads and show that they are comparable both to measurements of cytoskeletal systems and to theoretical predictions for active gels. Thus, we present a DNA-based active gel whose behavior highlights the universal aspects of nonequilibrium, motor-driven networks.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.1208732109