Federico I Rosell

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An (15)N-enriched sample of the yeast iso-1-ferricytochrome c triple variant (Lys72Ala/Lys79Ala/Cys102Thr) in an alkaline conformation was examined by NMR spectroscopy. The mutations were planned to produce a cytochrome c with a single conformer. Despite suboptimal conditions for the collection of spectra (i.e., pH approximately equal to 11), NMR remains a(More)
BphF is a small, soluble, Rieske-type ferredoxin involved in the microbial degradation of biphenyl. The rapid, anaerobic purification of a heterologously expressed, his-tagged BphF yielded 15 mg of highly homogeneous recombinant protein, rcBphF, per liter of cell culture. The reduction potential of rcBphF, determined using a highly oriented pyrolytic(More)
The yeast iso-1-cytochrome c variant Cys14Ser has been prepared in which one of the two thioether bonds by which the heme prosthetic group is normally bound to the protein has been eliminated. Comparison of the properties of this variant with those of the wild-type cytochrome provides insight into the role of this covalent attachment of the heme group to(More)
An efficient expression system [D. A. Dalton et al. Arch. Biochem. Biophys. 328, 1-8, 1996) for soybean nodule ascorbate peroxidase (APX) has, for the first time, been used to generate enzyme in large enough quantities for detailed biophysical analysis. The recombinant APX has been characterized by electronic absorption, EPR, NMR and circular dichroism(More)
The Zn-BChl-containing reaction center (RC) produced in a bchD (magnesium chelatase) mutant of Rhodobacter sphaeroides assembles with six Zn-bacteriochlorophylls (Zn-BChls) in place of four Mg-containing bacteriochlorophylls (BChls) and two bacteriopheophytins (BPhes). This protein presents unique opportunities for studying biological electron transfer, as(More)
The interactions of yeast iso-1 cytochrome c with bovine cytochrome c oxidase were studied using cytochrome c variants in which lysines of the binding domain were substituted by alanines. Resonance Raman spectra of the fully oxidized complexes of both proteins reveal structural changes of both the heme c and the hemes a and a3. The structural changes in(More)
Thermal denaturation of the human hemopexin-heme complex was investigated under a variety of solution conditions to identify factors that influence heme release. The midpoint temperature for the transition between the folded and folded states, T(m), of the hemopexin-ferriheme complex exhibits a significant dependence on pH. When the pH is reduced from 7 to(More)
A quadruple variant of horse heart myoglobin (Thr39Ile/Lys45Asp/Phe46Leu/Ile107Phe) that exhibits significantly (approximately 25-fold) greater peroxidase activity than the wild-type protein has been studied to determine its midpoint reduction potential (24(2) mV vs. SHE; pH 6.0, mu = 0.1 M, 25 degrees C) and to characterize the kinetics of its reaction(More)
The heme enzyme indoleamine 2,3-dioxygenase (IDO) was found to oxidize NADH under aerobic conditions in the absence of other enzymes or reactants. This reaction led to the formation of the dioxygen adduct of IDO and supported the oxidation of Trp to N-formylkynurenine. Formation of the dioxygen adduct and oxidation of Trp were accelerated by the addition of(More)
The functional properties of the recombinant C-terminal dimerization domain of the Pseudomonas aeruginosa Fur (ferric uptake regulator) protein expressed in and purified from Escherichia coli have been evaluated. Sedimentation velocity measurements demonstrate that this domain is dimeric, and the UV CD spectrum is consistent with a secondary structure(More)