A5039556554- Redox biology and oxidative stress
- Sulfur Compounds in Biology
- Enzyme Structure and Function
- Metal-Catalyzed Oxygenation Mechanisms
- Electron Spin Resonance Studies
- Trace Elements in Health
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Glutathione Transferases and Polymorphisms
- Click Chemistry and Applications
- Heat shock proteins research
- Protein Structure and Dynamics
- Synthesis and Characterization of Heterocyclic Compounds
- Genomics, phytochemicals, and oxidative stress
- bioluminescence and chemiluminescence research
- Biochemical effects in animals
- Protein Kinase Regulation and GTPase Signaling
- Heme Oxygenase-1 and Carbon Monoxide
- Mitochondrial Function and Pathology
- Nitric Oxide and Endothelin Effects
- Osteoarthritis Treatment and Mechanisms
- Melanoma and MAPK Pathways
- Computational Drug Discovery Methods
- Mass Spectrometry Techniques and Applications
- Electrochemical sensors and biosensors
- Advanced Proteomics Techniques and Applications
Wake Forest University
2015-2025
Atrium Health Wake Forest Baptist
1986-2022
Wake Forest Baptist Comprehensive Cancer Center
2018-2022
Poole Hospital
2009
Oregon State University
2001-2008
Institute of Cytochemistry and Molecular Pharmacology
2007
Laboratoire de Biochimie
2007
Elizabeth City State University
2005
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2002
CEA Grenoble
2002
Eukaryotic 2-Cys peroxiredoxins (2-Cys Prxs) not only act as antioxidants, but also appear to regulate hydrogen peroxide–mediated signal transduction. We showthat bacterial Prxs are much less sensitive oxidative inactivation than eukaryotic Prxs. By identifying two sequence motifs unique the and comparing crystal structure of a Prx at 2.2 angstrom resolution with other structures, we define structural origins sensitivity. suggest this adaptation allows floodgates, keeping resting levels...
A cDNA corresponding to a thiol-specific antioxidant enzyme (TSA) was isolated from rat brain library with the use of antibodies bovine TSA. The clone encoded an open reading frame capable encoding 198-residue polypeptide. and yeast TSA proteins show significant sequence homology 21-kDa component (AhpC) Salmonella typhimurium alkyl hydroperoxide reductase, we have found that AhpC exhibits activity. define family > 25 different present in organisms all kingdoms. similarity among members...
2-Cys peroxiredoxins (Prxs) are a large and diverse family of peroxidases which, in addition to their antioxidant functions, regulate cell signaling pathways, apoptosis, differentiation. These enzymes obligate homodimers (α2), utilizing unique intermolecular redox-active disulfide center for the reduction peroxides, known form two oligomeric states: individual α2 dimers or doughnut-shaped (α2)5 decamers. Here we characterize both oligomerization properties crystal structure bacterial Prx,...
The trapping of a sulfenic acid within the fully active C165S mutant AhpC peroxidase protein from Salmonella typhimurium was investigated. electrophilic reagent employed in these studies, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl), has previously been used to modify thiol, amino, and tyrosine hydroxyl groups proteins; at neutral pH only cysteinyl residues proteins are modified. peroxide-oxidized incubated with NBD-Cl gave product an absorbance maximum 347 nm, whereas thiol-NBD conjugate...
Peroxiredoxins (Prxs) make up a ubiquitous class (proposed EC 1.11.1.15) of cysteine-dependent peroxidases with roles in oxidant protection and signal transduction. An intriguing biophysical property typical 2-Cys Prxs is the redox-dependent modulation their oligomeric state between decamers dimers at physiological concentrations. The functional consequences this linkage are unknown, but on basis structural considerations, we hypothesized that decamer-building (dimer−dimer) interactions...
The two components, AhpF and AhpC, of the Salmonella typhimurium alkyl hydroperoxide reductase enzyme system have been overexpressed purified from Escherichia coli for investigations their catalytic properties. Recombinant proteins were isolated in high yield (25−33 mg per liter bacterial culture) shown to impart a degree protection against killing by cumene host E. cells. We developed quantitative enzymatic assays alone combined AhpF/AhpC which allowed us address such issues as substrate...
Peroxiredoxins (Prxs) are a widespread and highly expressed family of cysteine-based peroxidases that react very rapidly with H₂O₂, organic peroxides, peroxynitrite. Correct subfamily classification has been problematic because Prx subfamilies frequently not correlated phylogenetic distribution diverge in their preferred reductant, oligomerization state, tendency toward overoxidation. We have developed method uses the Deacon Active Site Profiler (DASP) tool to extract functional-site...
Cysteine sulfenic acid formation in proteins results from the oxidative modification of susceptible cysteine residues by hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite. This species represents a biologically significant occurring during oxidant signaling or stress, it can modulate protein function. Most methods to identify such oxidatively modified rely on monitoring loss one more thiol group(s) selective labeling nascent groups following reduction oxidized proteins. Our previous...
Reactive oxygen species (ROS), in particular, H2O2, is essential for full activation of VEGF receptor2 (VEGFR2) signaling involved endothelial cell (EC) proliferation and migration. Extracellular superoxide dismutase (ecSOD) a major secreted extracellular enzyme that catalyzes the dismutation to anchors EC surface through heparin-binding domain (HBD). Mice lacking ecSOD show impaired postnatal angiogenesis. However, it unknown whether ecSOD-derived H2O2 regulates signaling. Here we gene...
Typical 2-Cys peroxiredoxins (Prxs) are ubiquitous peroxidases that involved in peroxide scavenging and/or the regulation of signaling eukaryotes. Despite their prevalence, very few Prxs have been reliably characterized terms substrate specificity profile and redox potential even though these values important for gaining insight into physiological function. Here, we present such studies focusing on Salmonella typhimurium alkyl hydroperoxide reductase C component (StAhpC), an enzyme has...
Isoform-specific signaling of Akt, a major hub and prominent therapeutic target, remained poorly defined until recently. Subcellular distribution, tissue-specific expression, substrate specificity, posttranslational modifications are believed to underlie isoform-specific Akt. The studies reported here show inhibition Akt2 activity under physiologically relevant conditions oxidation created by PDGF-induced reactive oxygen species. Combined MS functional assays identified Cys124 located in the...