Open AccessMo K ‐ and L ‐edge X‐ray absorption spectroscopic study of the ADP·AlF 4 − ‐stabilized nitrogenase complex: comparison with MoFe protein in solution and single crystal
Author(s) -
Corbett Mary C.,
Tezcan F. Akif,
Einsle Oliver,
Walton Mika Y.,
Rees Douglas C.,
Latimer Matthew J.,
Hedman Britt,
Hodgson Keith O.
Publication year - 2005
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049504027827
Subject(s) - nitrogenase , absorption (acoustics) , x ray , chemistry , crystallography , physics , analytical chemistry (journal) , nuclear physics , optics , nitrogen fixation , nitrogen , chromatography , organic chemistry
The utility of using X‐ray absorption spectroscopy (XAS) to study metalloproteins and, specifically, the enzyme complex nitrogenase, is highlighted by this study comparing both the structural and Mo‐localized electronic features of the iron–molybdenum cofactor (FeMoco) in isolated MoFe protein and in the ADP·AlF 4 − ‐stabilized complex of the MoFe protein with the Fe protein. No major differences are found at Mo between the two protein forms. The excellent quality of the data at both the Mo K and L edges will provide a baseline for analysis of other intermediates in the nitrogenase cycle. A new capability to delineate various contributions in the resting state of FeMoco is being pursued through polarized single‐crystal XAS. The initial results point to the feasibility of using this technique for the analysis of scattering from the as yet unidentified atom at the center of FeMoco.