Mutations of the conserved residue Glu-92 to lysine, glutamine, and alanine have been performed in the recombinant ferredoxin I of spinach leaves. The purified ferredoxin mutants were found twice as active with respect to wild-type protein in the NADPH-cytochrome c reductase reaction catalyzed by ferredoxin-NADP+ reductase in the presence of ferredoxin. Cyclic voltammetry and EPR measurements showed that the mutations cause a change in the [2Fe-2S] cluster geometry, whose redox potential becomes approximately 80 mV less negative. These data point to a role of the Glu-92 side-chain in determining the low redox potential typical of the [2Fe-2S] cluster of chloroplast and cyanobacterial ferredoxins. Also a ferredoxin/ferredoxin-NADP+ reductase chimeric protein obtained by gene fusion was overproduced in Escherichia coli and purified. Fusion of the ferredoxin with its reductase causes only minor effects to the iron-sulfur cluster, as judged by cyclic voltammetry and EPR measurements.
Direct electrochemistry and EPR spectroscopy of spinach ferredoxin mutants with modified electron transfer properties / A. Aliverti, W.R. Hagen, G. Zanetti. - In: FEBS LETTERS. - ISSN 0014-5793. - 368:2(1995 Jul 17), pp. 220-224.
|Titolo:||Direct electrochemistry and EPR spectroscopy of spinach ferredoxin mutants with modified electron transfer properties|
ALIVERTI, ALESSANDRO (Primo)
ZANETTI, GIULIANA (Ultimo)
|Parole Chiave:||Cyclic voltammetry; EPR; Ferredoxin I; Ironsulfur cluster; Redox potential; Site-directed mutagenesis|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
Settore BIO/11 - Biologia Molecolare
Settore BIO/04 - Fisiologia Vegetale
Settore CHIM/03 - Chimica Generale e Inorganica
|Data di pubblicazione:||17-lug-1995|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/0014-5793(95)00648-S|
|Appare nelle tipologie:||01 - Articolo su periodico|