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Research has been conducted on the kynurenine pathway catabolites. The reaction of these catabolites with iron and copper and interactions with alpha-crystallins have been investigated.

Research has been conducted on the heterodimeric iron protein. The contributions provided by the iron protein subunits to the events controlled by hydrolysis and nucleotide binding have been studied.

Research has been conducted on the green sulfur bacteria Chlorobium tepidum and Prosthecochloris aestuarii. Electron transfer in the reaction center core complexes from these bacteria has been examined.

Research has been conducted on human lactoferrin (Lf) and serum transferrin (Tf). The iron-release profiles for Lf, Tf and their N-lobe half-molecules have been examined.

Research has been conducted on the O (sub)2 -carrying protein hemethyrin (Hr). Results indicate that a conserved sequence motof in all Hrs provides histidine and carboxylate ligands to the diiron active site.

Research has been conducted on the Rieske iron-sulfur protein. Electron transfer between this protein and cytochrome c (sub)1 has been investigated.

Research has been conducted on the biotin and lipoate synthases. The results of Mossbauer studies of (super)57 Fe-reconstituted biotin synthase are presented.

Research has been conducted on the iron-regulatory protein 1 (IRP1). The effect of the nitrogen monoxide donors on IRP1 RNA-binding activity in fibroblast lysates and whole cells.

Research has been conducted on the blue non-heme iron protein superoxide reductase (SOR). The investigation of the crystal structure of SOR in the oxidized and reduced forms is described.

Research has been conducted on the proximal heme iron ligands electronic characteristics in heme proteins. The role of the ligands in oxygen and peroxide activation has been investigated.

Research has been conducted on the effect of histidine ligand of human transferin on iron binding. Site-directed mutagenesis, spectroscopy and structural analysis are examined.

An analysis of the mechanism of ferroxidase reaction of ferritin shows that there exists a diferric mu-1,2 bridging transient peroxide intermediate similar to other O2-activating non-heme diiron proteins. This was evident in an experiment that characterized the intermediate and established the peroxodiferric assignment using the rapid freeze-quenching technique. Discrete vibrational modes were detected in the ferritin, suggesting that a single chromophore exists in a homogeneous state.

Aquantitative in vitro induction assay studies suggest that tetracycline-Fe2+ strongly induces the Tet repressor and oxidative cleavage of the Tet repressor-tetracycline-Fe2+ complex with H2O2 and ascorbate leads to an Fe2+-dependent specific dissociation of the protein. The redox-active oxo intermediates exhibit high reactivity at the proximity of the Fe2+-tetracycline chelator. Major cleavage occurs at the residues 104 and 105 of Tet repressor. Cleavage occurs less effectively at residues 56 and 136 while least efficient sites are residues 144 and 147.

Ferrous ion (Fe2+) from the Fe2+-ascorbate system catalyzes a specific oxidation of pigeon liver malic enzyme at Asp (258) and other amino acid residues that trigger enzyme inactivation. The oxidized enzyme induces affinity cleavage at the manganese ion-binding site of the malic enzyme and suggests the importance of Fe2+-ascorbate system as a potential affinity cleavage system for metal-binding sites. Malic enzyme needs divalent metal cations for catalysis.

The evidence of siderophore-iron reductase function of FhuF using electron paramagnetic resonance redox titrations is studied. The results show that FhuF plays an important role in iron removal from siderophores.