Computational Studies of a Protein-based

The design hypothesis, architectures, and computational modeling of a novel peptide-based nanoactuator are presented in this paper. We engineered the -helical coiled-coil portion of the yeast transcrip-tional activator peptide called GCN4 to obtain an environmentally responsive nanoactuator. The dimeric coiled-coil peptide consists of two identical approximately 4.5 nm long and approximately 3 nm wide polypeptide chains. The actuation mechanism depends on the modification of electrostatic charges along the peptide by varying the pH of the solution resulting in the reversible movement of helices and, therefore, creating the motion of an actuator. Using molecular dy-namics simulations we showed that pH changes led to a reversible opening of up to 1.5 nm which is approximately 150 % of the initial separation of the nanoactuator. We also investigated the forces gen-erated by the nanoactuator upon pH actuation, using a new metho