Fig. 1.

Revisiting catalysis enhanced diffusion of ALP. (A) Structure of ALP (Left) and the reaction it catalyzes (Right). The two protomers of ALP are colored in green and gray. pNPP (red and white) and zinc (black) are shown as spheres. During a reaction, ALP removes the phosphate group from pNPP and it has been shown previously that catalysis enhances the diffusivity of ALP. (B) Control experiments including pNPP with free dye, pNPP with wrong catalyst, and ALP reacting with alternative substrates are carried out to examine the role of catalysis on ALP diffusivity. (C) FCS estimates ensemble-averaged diffusion coefficients from autocorrelation analysis of fluorescence bursts in a confocal volume. (D) Principles of ABEL trap-based single-molecule diffusometry (see text for details). The diffusion coefficient of individual molecules can be measured for several seconds.