Figure 3. The R102Q mutation does not affect binding to IL1RAPL1 or Ca²⁺-binding.

(A,B) The endogenous tryptophan fluorescence of NCS-1 and NCS-1(R102Q) was monitored by excitation at 280 nm and scanning over a range of emission wavelengths before and after step-wise addition of CaCl₂ to give the indicated free Ca²⁺ concentrations. (C) The peak emission value for each emission trace was determined, normalised to the overall peak value for that experiment and the data expressed as the mean ± SEM (n = 10) for each free Ca²⁺ concentration tested. (D) NCS-1 and NCS-1(R102Q) were incubated with GST or GST-IL1RAPL1(569–644) in the absence or presence of the indicated free Ca²⁺ concentrations.