J. Phys. IV France 7 (1997) C2-611-C2-614
Difference EXAFS Studies of Nitrogenase and Nitrite Reductase Enzymes of the Nitrogen CycleR. R. Eady1, B. E. Smith1, Z. H. L. Abraham1, F. E. Dodd2, 3, J. G. Grossmann3, L. M. Murphy3, R. W. Strange3 and S. S. Hasnain3
1 Nitrogen Fixation Laboratory, John Innes Centre, Colney, Norwich NR4 7UH, UK
2 DeMontfort University, Leicester LEI 9BH, UK
3 CCLRC Daresbury Laboratory, Warrington WA4 4AD, UK
Difference EXAFS can be exploited to take full advantage of the power of the EXAFS technique in providing high resolution metrical information around the active centres of metalloenzymes during turnover and/or the binding of substrates or inhibitors. Difference EXAFS data are presented for (a) the Mo-nitrogenase of Klebsiella pneumoniae (Fe and Mo K-edges), under conditions of enzyme turnover designed to maximize the concentration of species of the MoFe protein containing reduced FeMoco, (b) the copper-containing dissimilatory nitrite reductase of Alcaligenes xylosoxidans. In this case, difference EXAFS data provide direct structure/function relationships for changes associated with binding of substrate to the oxidized enzyme and also the reduction of the enzyme.
© EDP Sciences 1997