Figure 2. Model ingredients.
(A) Size of adapted receptor complex 
(total number of Tar and Tsr receptors per complex) as function of ambient concentration 
(corresponding to adapted methylation level 
). Individual complex sizes (symbols) were obtained by fitting MWC model to dose-response curves for addition of MeAsp. These values were fitted by a linear function (line). (A Inset) Energy contribution to receptor complex free energy from methylation level 
per receptor dimer. Shown are fitting parameters for Tar receptors from [41] (symbols), as well as linear fit 
(in units of 
with 
the Boltzmann constant and 
absolute temperature). (B) Profile of concentration step change as measured experimentally using fluorescent marker (solid black line) [23], exponential fit used in dynamic MWC model for WT1 MeAsp profile (gray line; rate constants 
and 
), and perfect step change (black dashed line). Addition and removal times are marked by arrows. (B Inset) Response of mixed receptor complex to MeAsp removal for perfect (black dashed line) and exponentially fitted step change (gray line). (C) Typical time courses of receptor complex activity in response to two different MeAsp concentration step changes, 
(top) and 
(bottom), at ambient concentration 
. Experimental FRET measurement (thin black line), as well as dynamic MWC model for precise (gray lines) and imprecise adaptation (black lines; 
and 
). FRET and receptor complex activities were normalized by adapted pre-stimulus values before addition of MeAsp.