Engineered proteins have a wide range of applications in medicine, cosmetics, manufacturing, and biotechnology. We have developed an engineering process by which the activity of a traditional protein can be placed under the control of a specific wavelength of visible light.This innovation allows us to create versions of important bio-molecules with user-defined activity in time (when it’s active) and in space (where it’s active). As a result, we have engineered proteins with the potential to increase the throughput and yield of biopharmaceutical manufacturing, synergize with and enhance the precision of existing at-home cosmetic products, and ultimately improve both the efficacy and safety of breakthrough pharmaceuticals in cardiology, rheumatology, and oncology.