ATP:ADP antiporter mimics turbo-state.

(A) Overview of the models used in this figure. Model A and D are from Figure 1, model A–glyc is model A without glycosomal localization, as described in [31], model A+AAT is model A with an ATP:ADP antiporter. (B–C) Steady-state concentrations of glycosomal Glc-6-P and Fru-1,6-BP are depicted in the various models. (D) Increasing the activity of the ATP:ADP antiporter (V_{max,ATP:ADP antiporter}) in model D leads to a high risk of accumulation of hexose phosphates. The green line indicates the concentration of Fru-1,6-BP in the original model of glycolysis (17.2 mM, panel C, model A). Glc_e in this simulation is 25 mM. (E) Time course simulation of model D at 25 mM Glc_e and various values for the V_{max,ATP:ADP antiporter} parameter. Plotted is the concentration of glycosomal phosphates (ΣP similar as in Figure 2, moiety 5 in Table 2). ATP:ADP antiporter activity values below 1 nmol·min⁻¹·mg protein⁻¹ result in depletion of glycosomal phosphates (cf. Figure 2). k_TOX = 2 µl·min⁻¹·mg protein⁻¹ in all models. Solid lines indicate medians, shaded areas and error bars show interquartile ranges, as derived from the uncertainty modeling.