Interactive materials being responsive to a biocompatible stimulus represent a promising approach for future therapeutic applications. In this study, we present a novel biohybrid material synthesized from biocompatible components being stimulus-responsive to the pharmaceutically approved small-molecule novobiocin. The hydrogel design is based on the gyrase B (GyrB) protein, which is covalently grafted to multi-arm polyethylene glycol (PEG) using a Michael-type addition reaction. Upon addition of the GyrB-dimerizing substance coumermycin, stable hydrogels form which can be dissolved in a dose-adjustable manner by the antibiotic novobiocin. The switchable properties of this PEG-based hydrogel are favorable for future applications in tissue engineering and as externally controlled drug depot.