Fig. 4: The peak current does capture pre-equilibrium binding information.
From: Modeling the use of transient ligand binding information by AMPA receptors
a Steady state binding and peak current dose–response curves with binding and clamshell rates multiplied by the indicated factor. Peak current dose–response curves in color, with experimentally measured rates (factor 1) centrally (green), slower (yellow and red) and faster (cyan, blue, and purple) rates shifting right and left, respectively. Inset shows the model diagram with the modified rates highlighted in green. b EC50 ratio between the steady state binding and peak current dose–response curves for the explored binding and clamshell parameter space. Axes show the binding (kon) and clamshell closing (kcc) rates, and the model is run at constant KD (koff/kon) and Keq (kco/kcc). c EC50 ratio between the steady state binding and peak current dose–response curves for the explored binding and clamshell rates with clamshell equilibrium constant (Keq) equal to 1 and binding equilibrium constant (KD) equal to 1 µM. Axes show the binding (kon) and clamshell closing (kcc) rates. d EC50 ratio between the steady state binding and peak current dose–response curves for the explored opening and desensitization parameter space. Axes show the opening (ko) and desensitization (KD) rates, and the model is run at constant Keq (ko/kc) and Keq (kr/KD). b, d “Glu” marks the location in the parameter space where AMPAR stimulated with L-glutamate lies. d The arrow next to Glu indicates the range where L-glutamate: AMPAR lies due to changes in desensitization rate caused by subunit composition or association with accessory proteins (see Discussion).
