A5068781730- Pesticide Exposure and Toxicity
- Biochemical Acid Research Studies
- Metabolism and Genetic Disorders
- Cholinesterase and Neurodegenerative Diseases
- Biochemical and Molecular Research
- Insect and Pesticide Research
- Amino Acid Enzymes and Metabolism
- Pesticide and Herbicide Environmental Studies
- Paraoxonase enzyme and polymorphisms
- Enzyme Catalysis and Immobilization
- Chemical Reaction Mechanisms
- Computational Drug Discovery Methods
- Analytical Chemistry and Chromatography
- Mitochondrial Function and Pathology
- Vitamin C and Antioxidants Research
- Chemical Reactions and Isotopes
- thermodynamics and calorimetric analyses
- Diet and metabolism studies
- Molecular spectroscopy and chirality
- Dendrimers and Hyperbranched Polymers
- Pharmacological Effects and Toxicity Studies
- Folate and B Vitamins Research
- Chemical Thermodynamics and Molecular Structure
- RNA modifications and cancer
- Neuroscience and Neural Engineering
United States Army
2010-2020
DEVCOM Army Research Laboratory
2010-2019
CECOM Software Engineering Center
2018
United States Department of the Army
2010-2014
United States Army Medical Research Institute of Infectious Diseases
2013
Virginia Commonwealth University
2007
Kansas State University
2000-2005
Pfizer (United Kingdom)
2005
Organophosphorus compounds include many synthetic, neurotoxic substances that are commonly used as insecticides. The toxicity of these is due to their ability inhibit the enzyme acetylcholine esterase. Some most toxic organophosphates have been adapted for use chemical warfare agents; well-known GA, GB, GD, GF, VX, and VR. All contain a chiral phosphorus center, with SP enantiomers being significantly more than RP enantiomers. Phosphotriesterase (PTE) an capable detoxifying agents, but...
A catalytic nanoscavenger with long blood residence time provides long-term prophylactic protection against nerve agents in animal models.
Pyruvate dehydrogenase kinase (PDK) isoforms 2 and 3 were produced via co-expression with the chaperonins GroEL GroES purified high specific activities in affinity tag-free forms. By using human components, we have evaluated how binding to lipoyl domains of dihydrolipoyl acetyltransferase (E2) produces predominant changes rates phosphorylation pyruvate (E1) component by PDK2 PDK3. E2 assembles as a 60-mer its C-terminal domain has mobile connections an E1-binding then two domains, L2 L1 at N...
Pyruvate dehydrogenase kinase (PDHK) regulates the activity of pyruvate multienzyme complex. PDHK inhibition provides a route for therapeutic intervention in diabetes and cardiovascular disorders. We report crystal structures human isozyme 2 complexed with physiological synthetic ligands. Several PDHK2 disclosed have C-terminal cross arms that span large trough region between N-terminal regulatory (R) domains dimers. The containing bound ATP ADP demonstrate variation conformation active site...
The concept of using cholinesterase bioscavengers for prophylaxis against organophosphorous nerve agents and pesticides has progressed from the bench to clinical trial. However, supply native human proteins is either limited (e.g., plasma-derived butyrylcholinesterase erythrocytic acetylcholinesterase) or nonexisting (synaptic acetylcholinesterase). Here we identify a unique form recombinant that mimics enzyme assembly into tetramers; this provides extended effective pharmacokinetics...
Pyruvate dehydrogenase kinase 2 (PDK2) activity is enhanced by the dihydrolipoyl acetyltransferase core (E2 60mer) that binds PDK2 and a large number of its pyruvate (E1) substrate. With E2-activated PDK2, K+ at ∼90 mM Cl- ∼60 decreased Km for ATP competitive Ki ADP ∼3-fold inhibition. Comparing catalysis ± E2, E2 increased nearly 8-fold (from 5 to 39 μM), kcat ∼4-fold, requirement E1 least 400-fold. binding, measured cold-trapping technique, occurred two active sites with Kd μM, which...
Organophosphorus (OP) nerve agents are potent suicide inhibitors of the essential neurotransmitter-regulating enzyme acetylcholinesterase. Due to their acute toxicity, there is significant interest in developing effective countermeasures OP poisoning. Here we impart agent hydrolysis activity into human drug metabolism carboxylesterase 1. Using crystal structures target complex with as a guide, pair histidine and glutamic acid residues were designed proximal enzyme's native catalytic triad....
Pyruvate dehydrogenase kinase 2 (PDK2) activity is stimulated by NADH and plus acetyl-CoA via the reduction reductive acetylation of lipoyl groups dihydrolipoyl acetyltransferase (E2) component. Elevated K+ Cl- were needed for significant stimulation. Stimulation substantially increased both kcat Km ATP; fractional stimulation with level ATP. With an E2 structure lacking pyruvate (E1) binding domain, PDK2 was retained, E1 decreased, equilibrium dissociation constant ATP but remained much...
ABSTRACT Chemical warfare nerve agents (CWNAs) are extremely toxic organophosphorus compounds that contain a chiral phosphorus center. Undirected synthesis of G‐type CWNAs produces stereoisomers tabun, sarin, soman, and cyclosarin (GA, GB, GD, GF, respectively). Analytical‐scale methods were developed using supercritical fluid chromatography (SFC) system in tandem with mass spectrometer for the separation, quantitation, isolation individual GA, GF. Screening various stationary phases (CSPs)...
The mitochondrial folate transporter (MFT) was previously identified in human and hamster cells. Sequence homology of this protein with the inner membrane transporters suggested a domain structure which N- C-termini are located on intermembrane-facing surface, six membrane-spanning regions interspersed by two intermembrane loops three matrix-facing loops. We now report functional significance insertion c-myc epitope into series site-directed mutations at MFT residues highly conserved...
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionRegulatory Roles of the N-Terminal Domain Based on Crystal Structures Human Pyruvate Dehydrogenase Kinase 2 Containing Physiological and Synthetic LigandsThorsten R. Knoechel, Alec D. Tucker, Colin M. Robinson, Chris Phillips, Wendy Taylor, Peter J. Bungay, Shane A. Kasten, Thomas E. Roche, David G. BrownCite this: Biochemistry 2006, 45, 28, 8697–8698Publication Date (Web):June 27, 2006Publication...
The organophosphorus (OP) nerve agents are among the most toxic chemical compounds known. A subset of OP known as G‐series (including GA (tabun), GB (sarin), GD (soman) and GF (cyclosarin)) all share a chiral center at phosphorus atom, resulting in pair stereoisomers designated P(+) P(−); vitro capacity to inhibit acetylcholinesterase well vivo toxicity G‐agents is associated predominantly with P(−) isomer each compound. We have developed gas chromatography/mass spectrometry (GC/MS) method...
The atypical butyrylcholinesterase (aBuChE) from Oryzias latipes shares approximately 65% sequence similarity to both acetylcholinesterase and was studied for its capacity spontaneously reactivate following inhibition by organophosphorus nerve agents. full-length aBuChE protein expressed purified cabbage loopers (Trichoplusia ni larvae) infected with an orally active form of baculovirus. Like other cholinesterases, inhibited all G- V-type Interestingly, able undergo spontaneous reactivation...
Chemical warfare nerve agents are extremely toxic organophosphorus compounds that contain a chiral phosphorus center. Analytical scale methods using supercritical fluid chromatography (SFC) system in tandem with mass spectrometer were developed for the separation and detection of individual stereoisomers VX, VR, VS, analogs V1 thru V4. Separation was evaluated respect to parameter resolution (Rs) value 蠅1.7 indicating complete separation. The ChiralCel OD‐H column yielded Rs values >1.7...
Organophosphorus (OP) nerve agents are potent suicide inhibitors of the essential neurotransmitter-regulating enzyme acetylcholinesterase. Due to their acute toxicity, there is significant interest in developing effective countermeasures OP poisoning.Here we impart agent hydrolysis activity into human drug metabolism carboxylesterase 1.Using crystal structures target complex with as a guide, pair histidine and glutamic acid residues were designed proximal enzyme's native catalytic triad.The...