The presence of reactive oxygen species may lead to the oxidation of proteins. This process is part of our general metabolism, and several regulatory mechanisms involving natural antioxidants are in place to avoid excessive protein oxidation. However, this balance may be disturbed under several pathologic conditions and an excess of reactive oxygen species over these antioxidants may result in ...

Aging may alter protein metabolism during periods of metabolic and physiologic challenge. The purpose of this study was to assess the effects of age on whole-body amino acid turnover in response to eccentric exercise and hyperglycemia-induced hyperinsulinemia. 16 healthy men were divided into young (N=8) and older (N=8) groups. Protein metabolism was assessed using a [1-13C]-leucine isotopic tr...

Ferritins are spherical, cage-like proteins with nanocavities formed by multiple polypeptide subunits (four-helix bundles) that manage iron/oxygen chemistry. Catalytic coupling yields diferric oxo/hydroxo complexes at ferroxidase sites in maxi-ferritin subunits (24 subunits, 480 kDa; plants, animals, microorganisms). Oxidation occurs at the cavity surface of mini-ferritins/Dps proteins (12 subu...

13C NMR of the aromatic residues of Clostridium acidi-urici [Phe*]ferredoxin (a chemically modified ferredoxin in which a phenylalanyl residue replaces a tyrosyl residue) and Clostridium pasteurianum ferredoxin permits one to distinguish and probe each iron-sulfur (Fe&*) cluster neighboring the aromatic residues within each protein. This is because the ring carbon resonance shifts of the phenyl...

FixK2 is a regulatory protein that activates a large number of genes for the anoxic and microoxic, endosymbiotic, and nitrogen-fixing life styles of the α-proteobacterium Bradyrhizobium japonicum. FixK2 belongs to the cAMP receptor protein (CRP) superfamily. Although most CRP family members are coregulated by effector molecules, the activity of FixK2 is negatively controlled by oxidation of its...

Proteins with reactive sulfhydryls are central to many important metabolic reactions and also contribute to a variety of signal transduction systems. In this report, we examine the mechanisms of oxidative damage to the two reactive sulfhydryls of carbonic anhydrase III. Hydrogen peroxide (H2O2), peroxy radicals, or hypochlorous acid (HOCl) produced irreversibly oxidized forms, primarily cystein...

Glucose Oxidation in Heart-Type Fatty Acid Binding Protein Null Mice. (August 2006) Sean Adhikari, B.S., University of Washington Chair of Advisory Committee: Dr. Bert Binas Heart-type fatty acid binding protein (H-FABP) is a major fatty acid binding factor in skeletal muscles. Genetic lack of H-FABP severely impairs the esterification and oxidation of exogenous fatty acids in soleus muscles is...

Friedreich's ataxia is associated with a deficiency in frataxin, a conserved mitochondrial protein of unknown function. Here, we investigate the iron binding and oxidation chemistry of Escherichia coli frataxin (CyaY), a homologue of human frataxin, with the aim of better understanding the functional properties of this protein. Anaerobic isothermal titration calorimetry (ITC) demonstrates that ...