Figure 3. G6P (Fig. 3A) and PPi (Fig. 3B) hydrolysis in the presence of varying Mg²⁺ concentration, in the absence or in the presence of EDTA.

Digitonin-permeabilized hepatocytes were incubated in the presence of 5mM G6P (Fig. 3A) and 1mM PPi (Fig. 3B) in a medium containing either nominal 0mM or 0.25mM Mg²⁺ (Fig, 3A), or 0mM and 1mM Mg²⁺ (Fig. 3B). After 15 min incubation, the samples were split into two, one of which received a concentration of EDTA sufficient to chelate all external Mg²⁺ [20]. The inset in each figure reports the net change in hydrolysis at time=30min and time=45 min in the absence and in the presence of EDTA vs. time=15min. Data are means±S.E. of 5 different preparations. *Statistically significant vs. the corresponding sample in the presence of EDTA. Labeling in the inset is omitted for simplicity.