A5054689500- Hemoglobin structure and function
- Heme Oxygenase-1 and Carbon Monoxide
- Enzyme Structure and Function
- Antibiotic Resistance in Bacteria
- Biochemical and Molecular Research
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Pneumocystis jirovecii pneumonia detection and treatment
- Chromium effects and bioremediation
- Atmospheric and Environmental Gas Dynamics
- Hydrocarbon exploration and reservoir analysis
- Trace Elements in Health
- Metal-Catalyzed Oxygenation Mechanisms
- Methane Hydrates and Related Phenomena
- Microbial Natural Products and Biosynthesis
- Synthesis and Catalytic Reactions
- Forest Ecology and Biodiversity Studies
- Photosynthetic Processes and Mechanisms
- Erythrocyte Function and Pathophysiology
- Phytase and its Applications
- Antimicrobial Resistance in Staphylococcus
- Cancer-related gene regulation
- Forest Insect Ecology and Management
- Mycobacterium research and diagnosis
- Forest Biomass Utilization and Management
University of York
2024-2025
University of Alabama
2019-2023
Tuscaloosa City Schools
2019
Vanderbilt University
2013-2014
Vanderbilt University Medical Center
2013-2014
North Carolina State University
2009-2012
University of Essex
2010
Colorado Engineering (United States)
1993
In developed countries, people spend nearly 90% of their time indoors, where activities such as cooking and cleaning are significant sources air pollution, with consequent impacts on occupant health. Volatile organic compounds (VOCs), emitted can also escape into the urban outdoor environment contribute to secondary e.g. via production ozone particulate matter formation. This comes at a when successful regulation has led gradual decreases in emission from some traditional traffic. Despite...
Dehaloperoxidase (DHP) is a respiratory hemoglobin (Hb) that has been shown to catalyze the conversion of trihalophenols dihaloquinones in presence hydrogen peroxide. Ferric heme states resting DHP and free radical intermediates formed under H2O2 treatment were studied by low-temperature electron paramagnetic resonance spectroscopy range reaction times from 50 ms 2 min at three different pH values. Two high-spin ferric forms identified enzyme assigned open closed conformations distal...
Dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is a bifunctional enzyme that possesses both hemoglobin and peroxidase activities. Of two DHP isoenzymes identified to date, much of recent focus has been on A, whereas very little known pertaining activity, substrate specificity, mechanism function, or spectroscopic properties B. Herein, we report recombinant expression purification B, as well details our investigations into its catalytic cycle using biochemical assays,...
The Gram-positive pathogen Staphylococcus aureus is a leading cause of global morbidity and mortality. Like many multi-drug-resistant organisms, S. contains antibiotic-modifying enzymes that facilitate resistance to multitude antimicrobial compounds. FosB Mn(2+)-dependent fosfomycin-inactivating enzyme found in catalyzes nucleophilic addition either l-cysteine (l-Cys) or bacillithiol (BSH) the antibiotic, resulting modified compound with no bactericidal properties. three-dimensional X-ray...
The fosfomycin resistance enzymes, FosB, from Gram-positive organisms, are M(2+)-dependent thiol tranferases that catalyze nucleophilic addition of either L-cysteine (L-Cys) or bacillithiol (BSH) to the antibiotic, resulting in a modified compound with no bacteriacidal properties. Here we report structural and functional characterization FosB Bacillus cereus (FosB(Bc)). overall structure FosB(Bc), at 1.27 Å resolution, reveals enzyme belongs vicinal oxygen chelate (VOC) superfamily. Crystal...
The present work highlights the important role played by distal histidine in controlling binding of heme ligands dehaloperoxidase (DHP) as compared to myoglobin and peroxidases. In DHP is highly mobile undergoes a conformational change that places it within hydrogen-bonding distance anionic water, where strong hydrogen bonding can occur. detailed resonance Raman (RR) analysis at room temperature shows presence an equilibrium between 5-coordinate 6-coordinate (aquo) high-spin form. shifts...
The proximal side of dehaloperoxidase-hemoglobin A (DHP A) from Amphitrite ornata has been modified via site-directed mutagenesis methionine 86 into aspartate (M86D) to introduce an Asp-His-Fe triad charge relay. X-ray crystallographic structure determination the metcyano forms M86D [Protein Data Bank (PDB) entry 3MYN] and M86E (PDB 3MYM) mutants reveal structural origins a stable catalytic in DHP A. decrease rate H2O2 activation as well lowered reduction potential versus that wild-type...
Certain strains of the soil microorganism Streptomyces produce an antibiotic, fosfomycin [(1 R,2 S)-epoxypropylphosphonic acid], which is effective against both Gram-positive and Gram-negative pathogens by inhibiting first committed step in cell-wall biosynthesis. Fosfomycin resistance proteins are metallo-enzymes that known to inactivate antibiotic addition nucleophiles such as water, glutathione (GSH), l-cysteine bacillithiol (BSH) oxirane ring molecule. Progress characterisation FosB-type...
The crystal structures of the dehaloperoxidase-hemoglobin from A. ornata (DHP A) each report a crystallographic dimer in unit cell. Yet, largest interface observed is 450 Å2, an area significantly smaller than typical value 1200−2000 Å2 and contrast to extensive region other known dimeric hemoglobins. To examine oligomerization state DHP A solution, we used gel permeation by fast protein liquid chromatography small-angle X-ray scattering (SAXS). Gel experiments demonstrate that elutes as...
Dehaloperoxidase (DHP A), a unique multifunctional enzyme, from the marine annelid Amphitrite ornata dehalogenates 2,4,6-tribromophenol to form 2,6-dibromo-1,4-benzoquinone. The catalytic cycle of DHP is similar that horseradish peroxidase (HRP), involving high-valent ferryl heme and two single-electron transfers aromatic substrate enzyme. Like HRP, has been investigated as potential bioremediation However, fails enzyme because, unlike it an internal binding cavity on distal side capable...
We report new ruthenium complexes bearing the lipophilic bathophenanthroline (BPhen) ligand and dihydroxybipyridine (dhbp) ligands which differ in placement of OH groups ([(BPhen)
FosM from<italic>Mycobacterium abscessus</italic>is a Mn<sup>2+</sup>-dependent FosX-type hydrase.
The Gram-positive pathogen Staphylococcus aureus is a leading cause of antimicrobial resistance related deaths worldwide. Like many pathogens with multidrug-resistant strains, S. contains enzymes that confer through antibiotic modification(s). One such enzyme present in FosB, Mn2+-dependent l-cysteine or bacillithiol (BSH) transferase inactivates the fosfomycin. fosB gene knockout experiments show minimum inhibitory concentration (MIC) fosfomycin significantly reduced when FosB not present....
The Gram-positive pathogen Enterococcus faecium is one of the leading causes hospital-acquired vancomycin resistant enterococci (VRE) infections. E. has extensive multidrug resistance and accounts for more than two million infections in United States each year. FosB a fosfomycin enzyme found pathogens like faecium. Typically, enzymes are Mn2+ -dependent bacillithiol (BSH) transferases that inactivate through nucleophilic addition thiol to antibiotic. However, our kinetic analysis FosBEf...
Emission rates for volatile organic compounds (VOCs) have been quantified from frying, spice and herb cooking, cooking a chicken curry, using real-time selected-ion flow-tube mass spectrometry (SIFT-MS) controlled, laboratory-based experiments in semi-realistic kitchen. Emissions 7 different oils were investigated during the frying of wheat flatbread (puri). These emissions dominated by ethanol, octane, nonane variety aldehydes, including acetaldehyde, heptenal hexanal, average concentration...
High-throughput virtual screening has identified several new inhibitors of FosB from methicillin-resistant Staphylococcus aureus .
We have performed and analyzed the first combined 151 Eu 57 Fe nuclear resonant vibrational spectroscopy (NRVS) for naturally abundant KEu( iii )[Fe( ii )(CN) 6 ] or Eu( complex.