Displacement Statistics of Unhindered Single Molecules Show no Enhanced Diffusion in Enzymatic Reactions.

Recent studies have sparked debate over whether catalytic reactions enhance the diffusion coefficients of enzymes. Through high statistics of the transient (600 μs) displacements of unhindered single molecules freely diffusing in common buffers, we here quantify for four enzymes under catalytic turnovers. We thus formulate how ∼ ±1% precisions may be achieved for , and show no changes in diffusivity for catalase, urease, aldolase, and alkaline phosphatase under the application of wide concentration ranges of substrates. Our single-molecule approach thus overcomes potential limitations and artifacts underscored by recent studies to show no enhanced diffusion in enzymatic reactions.