Motility and Structural Polymorphism of Polymer–Actin Complex Gel

We report a soft gel machine reconstructed from muscle proteins. We have found that chemically cross-linked polymer–actin complex gel can move on myosin coated surface with a velocity as high as that of native F-actin, by coupling to ATPhydrolysis. Additionally, it is shown that the velocity and motional pattern of polymer–actin complex gel depends on the morphology of polymer-complex gels. Since the designing of functional actuator into well-defined size and morphology is important, the structural behavior of polymer–actin complexes has been investigated. This result shows that the morphology and growth size of polymer–actin complex can be controlled by change of electrostatic interaction between F-actins and polycations. Our results indicate that bio actuator with desired shape can be created by using polymer–actin complex.