Fig. 2
From: In vitro fusion of single synaptic and dense core vesicles reproduces key physiological properties
Purified secretory vesicles contain functional V-ATPase acidification of a synaptic vesicles, b dense-core vesicles, or c insulin vesicles. Bulk acridine orange fluorescence was monitored in the presence of the secretory vesicle and valinomycin (black line). Addition of ATP drives progressive self-quenching of the acridine orange fluorescence due to concentration into the interior of the secretory vesicle. The addition of CCCP dissipates the pH gradient causing an increase in acridine orange fluorescence. The presence of bafilomycin inhibits the proton pump preventing the acidification of the secretory vesicles (blue traces)
