We have recently developed a novel method to reversibly control protein conformation with simple light illumination. This method relies on the interaction of proteins with photoresponsive “azoTAB” surfactants that can be switched from the photo-active to a photo-passive state with exposure to visible or UV light, respectively. The active surfactant binds to and unfolds proteins, while the passive surfactant dissociates from proteins inducing refolding. To examine the partially-folded structures that result, we have utilized small-angle neutron scattering (SANS) along with shape-reconstruction algorithms. Briefly, shape reconstruction involves optimizing the positions of the “scattering centers” within the protein to best fit the SANS data. With azoTAB under visible light, lysozyme unfolding is localized to a swelling of the hinge region connecting the alpha and beta domains, while UV illumination refolds lysozyme to a native-like conformation. To investigate the effects of hinge swelling on protein dynamics, we have performed neutron spin echo (NSE) experiments. NSE can access relaxational dynamics over time scales from 0.01–100 ns and length scales from 10–150 Å, appropriate for the study of domain motions within proteins. Interestingly, NSE detects internal motions within lysozyme in the presence of active surfactant (visible light), while converting the surfactant to the passive form with UV light results in a “dormant” protein in the nanosecond/nanometer regime, similar to native lysozyme. Notably, these internal motions are accompanied by a 7x “superactivity” of the enzyme versus the native state. AzoTAB induces unique allosteric control of enzyme activity through hinge swelling and enhancing enzyme flexibility.