Figure 2.

Schematic drawing of reaction cycle for NKCC1 cotransporter. $k_{on}^{ion}$, association constant; $k_{\text{off}}^{\text{X}}$, dissociation rate constants for ion X; $k_{\text{f}}^{\text{empty}}$, forward rate constants for the empty cotransporter; $k_{\text{b}}^{\text{empty}}$, backward rate constants for the empty cotransporter; $k_{\text{f}}^{\text{full}}$, forward rate constants for the ion-filled cotransporter; $k_{\text{b}}^{\text{full}}$, backward rate constants for the ion-filled cotransporter; [X]_o, external concentration of ion X; [X]_i, internal concentration of ion X.