Figure 5.

Simulations showing the mechanism for persistence of slow oscillations in $\beta$-PFKM-KO islets. In the IOM, slow oscillations persist when PFKM is knocked out due to increased activity of PFKP. The black traces are for WT conditions (with PFKM present), and the red traces are after PFKM knockout. (A) The free cytosolic Ca²⁺ concentration exhibits slow oscillations for both WT and KO conditions. (B and C) The ATP (B) and FBP (C) concentrations exhibit slow oscillations before and after the KO. (D) Metabolic flux through the PFKM enzymatic reaction is eliminated once the PFKM enzyme is knocked out. (E) The metabolic flux through PFKP is very small in the WT case but in the KO is comparable to the WT PFKM flux. (F) The total PFK metabolic flux is the same before and after the removal of PFKM. The time courses were generated with $g_{\text{K}\left(\text{Ca}\right)}=150\text{pS}$ and $v_{\text{PDH}}=0.4\text{μM}{\text{ms}}^{-1}$. For the WT simulation (black), $v_{\text{PFK}-\text{M}}=0.01\text{μM}{\text{ms}}^{-1}$ and $v_{\text{PFK}-\text{C}}=0.01\text{μM}{\text{ms}}^{-1}$ . PFKM is knocked out (red) by setting $v_{\text{PFK}-\text{M}}=0\text{μM}{\text{ms}}^{-1}$. To see this figure in color, go online.