Ballistic flight of enzymes away from reactants

Too much remains speculative about how the internal dynamics of enzymes relates to catalytic function, owing to lack of appropriate methods to detect millisecond time scales over sufficiently small observation windows. Here, we used super-resolution microscopy (stimulated emission-depletion fluorescence correlation spectroscopy, STED-FCS) to observe an active enzyme spontaneously migrate toward the direction of lower reactant (substrate) concentration using the run-and-tumble method, which is a strategy similar to that of swimming microorganisms. This we modeled theoretically to explain why it leads to anti-chemotaxis. Experimentally, we showed that enhanced enzyme mobility is generated by super-diffusive kicks at the substrate turnover frequency. The results help us understand activities of enzymes, and furthermore to design and use a synthetic self-propelled swimmer relevant to “active matter.”