Fig. 4: Simulation of HEK293T cell binding dynamics demonstrates a strong alignment with the in vitro experimental observations of OXTR activation (mathematical model simulation data).

The OXTR complex (OXTRC) formation for all variants at equilibrium in OXTR-transfected a–c HEK293T cells and d–f human myometrial cells treated with 10 pM (a, d), 10 nM (b, e), and 1 μM c, f OXT treatments. The plot shows the concentration of bound wild-type (WT) OXTR and 5 variant OXTRs in pM on the left Y-axis and in complexes/cell on the right Y axis. The zoomed-in plot is shown as inset plot in a, b, and d. The black solid line represents wild type, the blue dotted line represents variant L206V, the green dashed-dotted line represents variant P108A, the purple point–marked line represents variant V45L, the magenta circle–marked line represents variant E339K, and the red dashed line represents variant V281M. The initial concentrations used for OXTR (nM) on the surface of a HEK293T cell were as follows: [WT] = 254 nM, [V281M] = 128 nM, [P108A] = 309 nM, [L206V] = 355 nM, [V45L] = 237 nM, [E339K] = 168 nM. The initial concentrations used for OXTR (nM) on the surface of a myometrial cell were as follows: [WT] = 1.68 nM, [V281M] = 0.75 nM, [P108A] = 2.66 nM, [L206V] = 3.04 nM, [V45L] = 1.96 nM, [E339K] = 1.19 nM.