Fig 3.

Spectral properties of CaCYP51, Δ60HsCYP51, and HsCYP51. (A and B) Absolute oxidized absorption spectra (A) between 700 and 300 nm and reduced carbon monoxide difference spectra (B) between 500 and 400 nm were determined using 5 μM CaCYP51 (line 1), Δ60HsCYP51 (line 2), and HsCYP51 (line 3), with matched quartz semi-micro cuvettes with 10-mm light paths. (C) Type I difference spectra were obtained by progressive titration of lanosterol against 5 μM solutions of the three CYP51 proteins using quartz semi-micro cuvettes with 4.5-mm light paths. (D) Lanosterol saturation curves were constructed for the CaCYP51 (●), Δ60HsCYP51 (○), and HsCYP51 (×) proteins. All spectral determinations were performed in triplicate, although the results from only one replicate are shown.