Dynamic Hydrogels: Translating a Protein Conformational Change into Macroscopic Motion

Natural inspiration: A bioinspired functional material in the form of a hydrogel created by cross-linking an engineered version of calmodulin, a protein which undergoes a conformational change in response to ligand binding (see schematic representation), with a four-armed poly(ethylene glycol) molecule terminated with acrylate groups decreased in volume by 20 % when treated with the ligand trifluoperazine. Multiple cycles of gel swelling and shrinkage were possible.