@article {2469,
	title = {Metal binding to the tetrathiolate motif of desulforedoxin and related polypeptides},
	journal = {Journal of Biological Inorganic Chemistry},
	volume = {3},
	number = {6},
	year = {1998},
	note = {<p>Times Cited: 6</p>
},
	month = {Dec},
	pages = {643-649},
	abstract = {<p>Desulforedoxin and the N-terminus of desulfoferrodoxin share a 36 amino acid domain containing a (Cys-S)(4) metal binding site. Recombinant forms of desulforedoxin, an N-terminal fragment of desulfoferrodoxin, and two desulforedoxin mutant proteins were reconstituted with Fe3+ Cd2+, and Zn2+ and relative metal ion affinities assessed by proton titrations. Protons compete with metal for protein ligands, a process that can be followed by monitoring the optical spectrum of the metal-protein complex as a function of pH. For all polypeptides, Fe3+ bound with the highest affinity, whereas the affinity of Zn2+ was greater than Cd2+ in desulforedoxin and the N-terminal fragment of desulfoferrodoxin, but this order was reversed in desulforedoxin mutant proteins. Metal binding in both mutants was significantly impaired. Furthermore, the Fe3+ complex of both mutants underwent a time-dependent bleaching process which coincided with increased reactivity of cysteine residues to Ellman{\textquoteright}s reagent and concomitant metal dissociation. It is hypothesized that this results from an autoredox reaction in which Fe3+ is reduced to Fe2+ with attendant oxidation of ligand thiols.</p>
},
	isbn = {0949-8257},
	url = {http://dx.doi.org/10.1007/s007750050278},
	author = {Kennedy, M. and Yu, L. and Lima, M. J. and Ascenso, C. S. and Czaja, C. and Moura, I. and Moura, J. J. G. and Rusnak, F.}
}
