EXAFS of the type‐1 copper site of rusticyanin

FEBS Letters

Holt, Steven D.¹  Ingledew, W.John³  Diakun, Gregory P.⁴  Piggott, Brian¹  Feiters, Martinus C.² 

[1] Inorganic Chemistry Research Laboratory, Division of Chemistry, School of Natural Sciences. Hatfield Polytechnic, Hatfield, Herts, AL10 9AB, UK;Department of Organic Chemistry, Catholic University of Nijmegen, Toernooiveld, NL-6525 ED Nijmegen, The Netherlands;Department of Biochemistry and Microbiology, University of St. Andrews, Fife, Scotland, KY16 9AL, UK;Science and Engineering Research Council, Daresbury Laboratory, Warrington WA4 4AD, UK

关键词: Rusticyanin;    EXAFS;    Blue-copper protein;    Redox potential;    Thiobacillus ferrooxidans;    EXAFS;    extended x-ray absorption fine structure;    1H-NMR;    proton nuclear magnetic resonance;   

DOI  :  10.1016/0014-5793(90)81133-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Extended X-ray absorption fine structure (EXAFS) spectra at the Cu K-edge have been recorded of the oxidized and reduced form at pH 3.5 of rusticyanin, the type-1 or ‘blue’-copper protein from Thiobacillus ferrooxidans. The EXAFS of oxidized rusticyanin is well simulated with models assuming a ligand set of 2 N(His) and 1 S(Cys) at 1.99 and 2.16 Å, respectively. Upon reduction, the average Cu-N ligand distance increases by approx. 0.08Å. For both redox states studied, the fit by the simulation is significantly improved by including a contribution of an additional sulfur ligand at approx. 2.8 Å. From comparison with structural data of other blue-copper proteins, it is concluded that the copper coordination environment is relatively rigid, which may be a clue to its high redox potential.

【 授权许可】

Unknown