FIGURE 3. Collagen binding to TRα2β1-Fc cation-binding site mutants.

Culture supernatants from transfected CHO L761h cells with TRα2 and wild-type TRβ1 or TRβ1 mutated at the MIDAS (D130A), ADMIDAS (D137A, D138A) or LIMBS (D226A, E169A, E169D) were analysed in Fc-capture assays, performed in the presence of 5 mM Mg²⁺ (A) or 1 mM Mn²⁺ (B) in the absence (open bars) or presence of the activating mAb TS2/16 (diagonally-hatched bars). Absorbance values and error bars represent the mean and standard deviation of three replicate wells from one experiment, representative of three separate experiments. Non-specific collagen binding (as estimated from the binding to wells treated with supernatant from mock-transfected cells) has been subtracted in this and all subsequent figures.