Dynamic hydrogels: Translating a protein conformational change into macroscopic motion

(Figure Presented) 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 polyethylene 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. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.