Figure 3.

Kinetics of ATP-energized uptake of CSG and CE-GS by vacuolar membrane vesicles. Uptake of CSG (A) or CE-GS (B) was measured at 25°C in standard uptake medium in the presence or absence of ATP. Uptake was allowed to proceed for 20 min (CSG) or 15 min (CE-GS) before rapid filtration and determination of the amount of the compound taken up by LC-MS. The values shown are the means of duplicate measurements minus the amount of compound that was taken up in the absence of ATP. Insets, Eadie-Hofstee (v/[S] versus v) plots, where v = velocity of uptake and [S] = substrate concentration.