Local atomic structure of HSA-heme-Fe(III), ibuprofen-HSA-heme-Fe(III), and warfarin-HSA-heme-Fe(III) around the heme-Fe(III) atom as obtained by EXAFS data analysis, compared with the average coordination distances of models (PDB and SMD).

The standard uncertainty on the parameters refined for the EXAFS data analysis are reported in parenthesis (last digit variation). The and R2 parameters (EXAFS analysis) are reported (see text). The last right columns contain the number of neighbors and average distance of the structure used for XANES models. The C4 coordination shell is included in the XANES simulations.
aCoordination numbers were fixed to the crystallographic values. Noticeably, refining NI and NII in HSA-heme-Fe(III) data, they changed less than 10% well within the estimated uncertainty. Therefore, we can safely assume correct the five-coordination of the heme-Fe(III) atom in the HSA-heme-Fe(III)-complex in solution fixing NI = 4 and NII = 1.