Catalytic enzymes are active matter

Recent studies suggest that the enhanced diffusion of catalytically-active enzymes is promoted by super-diffusive “kicks” generated by the catalytic events. Pursuing this idea, we have explored methods to vary systematically the turnover frequency, k_cat, which defines how many substrate molecules are consumed in a given time. Our measurements using fluorescence correlation spectroscopy in super-resolution mode (FCS-STED) enable us to illuminate this matter. The contrast between motions in the presence of inhibitor and of substrate is especially interesting.