Hendrickson W A, Co M S, Smith J L, Hodgson K O, Klippenstein G L
Proc Natl Acad Sci U S A. 1982 Oct;79(20):6255-9. doi: 10.1073/pnas.79.20.6255.
X-ray absorption spectroscopy has been used to study the dimeric iron center in azidomethemerythrin from Phascolopsis gouldii. Absorption edge data confirm that the two iron atoms are present as Fe(III) and suggest a hexa-coordination site for each of the iron atoms. The extended x-ray absorption fine structure (EXAFS) analysis provides direct structural evidence of a mu-oxo bridge between the two iron atoms at an average Fe-O distance of 1.71-1.76 A. Analysis using a multiple-scattering formalism calculates upper limits of 165 degrees for the Fe-O-Fe bridging angle and 3.38 A for the Fe-Fe distance. This result agrees with current crystallographic models being determined by refinement of structures of two azidomethemerythrins.
X射线吸收光谱已被用于研究来自古氏管须蟹的叠氮高铁血蓝蛋白中的二聚体铁中心。吸收边数据证实两个铁原子以Fe(III)形式存在，并表明每个铁原子有一个六配位位点。扩展X射线吸收精细结构（EXAFS）分析提供了两个铁原子之间存在μ-氧桥的直接结构证据，平均Fe-O距离为1.71 - 1.76 Å。使用多重散射形式进行的分析计算出Fe-O-Fe桥连角的上限为165度，Fe-Fe距离的上限为3.38 Å。该结果与通过对两种叠氮高铁血蓝蛋白结构进行精修而确定的当前晶体学模型一致。
