TY - JOUR
T1 - Spectroscopic studies of cobalt and nickel substituted rubredoxin and desulforedoxin
AU - Moura, Isabel
AU - Teixeira, Miguel
AU - Moura, José J. G.
AU - LeGall, Jean
N1 - NIGMS NIH HHS (GM41482-03)
PY - 1991/11/1
Y1 - 1991/11/1
N2 - The single iron site of rubredoxin was replaced by nickel and cobalt. The near-infrared/visible/UV spectra of these metal derivatives show ligand-field transitions and charge-transfer bands which closely resemble those of simple tetrathiolate complexes, indicating a tetrahedral arrangement of the sulfur cysteinyl ligands around the metal core. The 1H NMR spectra of the nickel and cobalt derivatives reveal extremely low-field contact shifted resonances of one proton intensity assigned to β-CH2 and α-CH cysteinyl protons. Other well resolved resonances shifted out of the main protein spectral envelope are also observed and probably arise from contact plus pseudocontact shift mechanisms. Rubredoxins from different sulfate reducers were metal substituted and assignments of aliphatic protons are tentatively proposed, taking advantage of the amino acid sequence homologies. The present data is promising in terms of structural analysis of the coordination sphere of the metal core. It was also shown that replacement of the iron atom of desulforedoxin, a close analogue of rubredoxin, by cobalt and nickel was possible.
AB - The single iron site of rubredoxin was replaced by nickel and cobalt. The near-infrared/visible/UV spectra of these metal derivatives show ligand-field transitions and charge-transfer bands which closely resemble those of simple tetrathiolate complexes, indicating a tetrahedral arrangement of the sulfur cysteinyl ligands around the metal core. The 1H NMR spectra of the nickel and cobalt derivatives reveal extremely low-field contact shifted resonances of one proton intensity assigned to β-CH2 and α-CH cysteinyl protons. Other well resolved resonances shifted out of the main protein spectral envelope are also observed and probably arise from contact plus pseudocontact shift mechanisms. Rubredoxins from different sulfate reducers were metal substituted and assignments of aliphatic protons are tentatively proposed, taking advantage of the amino acid sequence homologies. The present data is promising in terms of structural analysis of the coordination sphere of the metal core. It was also shown that replacement of the iron atom of desulforedoxin, a close analogue of rubredoxin, by cobalt and nickel was possible.
UR - http://www.scopus.com/inward/record.url?scp=0026091738&partnerID=8YFLogxK
U2 - 10.1016/0162-0134(91)84025-5
DO - 10.1016/0162-0134(91)84025-5
M3 - Article
C2 - 1664851
AN - SCOPUS:0026091738
SN - 0162-0134
VL - 44
SP - 127
EP - 139
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
IS - 2
ER -