A) Normalized circular dichroism spectra (25 °C) of AHis (red), BThr (blue), AHis:BThr (1:1 mixture black), and (DPP)Zn:AHis:BThr (1:1:1 mixture; purple); the inset shows the corresponding visible/Soret spectrum). B) Thermal unfolding profiles (λprobe = 222 nm) of AHis (red, TM = 44 °C), BThr (blue, TM = 54 °C), AHis:BThr (black, TM = 56 °C), and complexed (DPP)Zn:AHis:BThr (purple, TM = 63 °C). The fraction folded was estimated using the ellipticity relative to folded and unfolded baselines.