Fig 6. Mean concentrations of 1,2-PD and propionaldehyde in the MCP (P_MCP; A_MCP) and cytosol (P_cyto; A_cyto) as a function of (A) k_c when $k_c=k_c^A=k_c^P$; (B) $k_c^A$ when $k_c^P={10}^{-5}$ cm/s; and (C) $k_c^P$ when $k_c^A={10}^{-5}$ cm/s. Saturation phase space of PduCDE and PduP/Q with respect to (D) $k_c^A$ and $k_c^P$.

In (A), (B), and (C), K_M of PduCDE and PduP/Q are shown as solid lines. The baseline permeabilities are shown with a black dashed line. In (D), regions of saturation (concentration of substrate > K_M of the appropriate enzyme) are plotted in blue when PduCDE and PduP/Q are saturated, orange when only PduCDE is saturated, and in grey when neither enzyme is saturated. Red solid lines indicate when A_cyto is 1 μM; red dashed lines indicate when A_cyto is 10 nM. Black dashed lines indicate the baseline parameter values used in the model of the Pdu MCP. Green line indicates $k_c^A=k_c^P$.