A5077074927- Nitric Oxide and Endothelin Effects
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Reproductive Biology and Fertility
- Reproductive System and Pregnancy
- Intestinal and Peritoneal Adhesions
- Ovarian function and disorders
- Heme Oxygenase-1 and Carbon Monoxide
- Hemoglobin structure and function
- Endometriosis Research and Treatment
- Birth, Development, and Health
- Vanadium and Halogenation Chemistry
- Vitamin C and Antioxidants Research
- Sperm and Testicular Function
- Porphyrin and Phthalocyanine Chemistry
- Electron Spin Resonance Studies
- Photoreceptor and optogenetics research
- bioluminescence and chemiluminescence research
- Porphyrin Metabolism and Disorders
- Metal complexes synthesis and properties
- Circadian rhythm and melatonin
- Erythrocyte Function and Pathophysiology
- Metal-Catalyzed Oxygenation Mechanisms
- Hernia repair and management
- Uterine Myomas and Treatments
- Hydrogen's biological and therapeutic effects
Wayne State University
2016-2025
Wayne State College
2006-2013
Michigan United
2012
Children's Hospital of Michigan
2006-2008
Cleveland Clinic
1995-2006
Texas A&M University
1992-2006
Detroit Medical Center
2005-2006
University School
1996-2006
Canisius-Wilhelmina Ziekenhuis
2001
University of Virginia
2001
Nitrotyrosine is widely used as a marker of post-translational modification by the nitric oxide (<sup>⋅</sup>NO, nitrogen monoxide)-derived oxidant peroxynitrite (ONOO<sup>−</sup>). However, since discovery that myeloperoxidase (MPO) and eosinophil peroxidase (EPO) can generate nitrotyrosine via oxidation nitrite (NO <mml:math><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:math>), several questions have arisen. First, relative...
Nitric oxide (NO) is synthesized within the immune, vascular, and nervous systems, where it acts as a wide-ranging mediator of mammalian physiology. The NO synthases (EC 1.14.13.39) isolated from neurons or endothelium are calmodulin dependent. Calmodulin binds reversibly to neuronal synthase in response elevated Ca2+, triggering its production by an unknown mechanism. Here we show that binding allows NADPH-derived electrons pass onto heme group synthase. Calmodulin-triggered electron...
We now show that NO serves as a substrate for multiple members of the mammalian peroxidase superfamily under physiological conditions. Myeloperoxidase (MPO), eosinophil peroxidase, and lactoperoxidase all catalytically consumed in presence co-substrate hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>). Near identical rates consumption by peroxidases were observed presence<i>versus</i> absence plasma levels Cl<sup>−</sup>. Although buffer accelerated superoxide-generating system, subsequent...
In this study, we show that oxygen regulates nitric oxide (NO) levels through effects on NO synthase (NOS) enzyme kinetics. Initially, synthesis in the static lung was measured bronchiolar gases during an expiratory breath-hold normal individuals. accumulated exponentially to a plateau, indicating balance between production and consumption lung. Detection of NO2-, NO3-, S-nitrosothiols epithelial lining fluids confirmed by chemical reactions Interestingly, alveolar gas (estimated from at...
A wealth of evidence supports increased NO (NO ⋅ ) in asthma, but its roles are unknown. To investigate how participates inflammatory airway events we measured and chemical reaction products [nitrite, nitrate, S -nitrosothiols (SNO), nitrotyrosine] before, immediately 48 h after bronchoscopic antigen (Ag) challenge the peripheral airways atopic asthmatic individuals nonatopic healthy controls. Strikingly, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym}...
In neuronal nitric-oxide synthase (NOS), electron transfer proceeds across domains in a linear sequence from NADPH to flavins heme, with calmodulin (CaM) triggering the interdomain heme (Abu-Soud, H. M., and Stuehr, D. J. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 10769-10772). Here, we utilized NOS devoid of its bound tetrahydrobiopterin (apo-NOS) examine whether is responsible for CaM's activation NO synthesis, substrate-independent oxidation, cytochrome c ferricyanide reduction. Of four...
Protein nitration and lipid peroxidation are implicated in the pathogenesis of atherosclerosis; however, neither cellular mediators nor reaction pathways for these events vivo established. In present study, we examined chemical available to monocytes generating reactive nitrogen species explored their potential contribution protein biological targets. Isolated human activated media containing physiologically relevant levels nitrite (NO(2)(-)), a major end product nitric oxide ((*)NO)...
Neuronal NO synthase (NOS) is a flavin-containing hemeprotein that generates from L-arginine, NADPH, and O2. has recently been proposed to autoinhibit NOS. We have investigated whether NOS heme-NO complex forms during aerobic steady-state catalysis. Visible resonance Raman spectra recorded synthesis by showed the majority of enzyme (70-90%) was present as its ferrous-nitrosyl complex. Ferrous-nitrosyl formed only in coincident presence Its level remained constant until NADPH exhausted, after...
Myeloperoxidase (MPO), an abundant protein in neutrophils, monocytes, and subpopulations of tissue macrophages, is believed to play a critical role host defenses inflammatory injury. To perform these functions, array diffusible radicals reactive oxidant species may be formed through oxidation reactions catalyzed at the heme center enzyme. inducible nitric-oxide synthase are both stored secreted from primary granules activated leukocytes, nitric oxide (nitrogen monoxide; NO) reacts with iron...
The nitric oxide synthases (NOS) are the only heme-containing enzymes that require tetrahydrobiopterin (BH4) as a cofactor. Previous studies indicate fully reduced (i.e., tetrahydro) form of BH4 can support NO synthesis. Here, we characterize pterin-free inducible NOS (iNOS) and iNOS reconstituted with eight different tetrahydro- or dihydropterins to elucidate how changes in pterin side-chain structure ring oxidation state regulate iNOS. Seven enzyme properties important for catalysis...
Nitric oxide synthases (NOS) are hemeproteins that catalyze oxidation of L-arginine to nitric (NO) and citrulline. The NOS heme iron is expected participate in oxygen activation during catalysis, but its interactions with O2 not characterized. We utilized the heme-containing oxygenase domain neuronal (nNOSoxy) stopped-flow methods study formation autooxidative decomposition nNOSoxy oxygenated complex at 10 degrees C. Mixing ferrous air-saturated buffer generated a transient species...
Neuronal nitric-oxide synthase (NOS-1) is a hemeprotein that generates NO and citrulline from L-arginine, O2, NADPH. During catalysis, majority of NOS-1 binds self-generated converts to ferrous-NO complex, which causes it operate at fraction its maximum possible activity during the steady state (Abu-Soud, H. M., Wang, J., Rousseau, D. L., Fukuto, Ignarro, L. Stuehr, J. (1995) Biol. Chem. 270, 22997-23006). To examine how complex formation affects O2 response NOS-1, we measured rates...
Rat neuronal NO synthase (nNOS) is comprised of a flavin-containing reductase domain and heme-containing oxygenase domain. Calmodulin binding to nNOS increases the rate electron transfer from NADPH into its flavins, triggers flavins heme, activates synthesis, reduction artificial acceptors such as cytochrome c. To investigate what role plays in calmodulin's activation these functions, we overexpressed form (amino acids 724-1429) yeast Pichia pastoris that for first time exhibits complete...
Heme iron reduction in the nitric-oxide synthases (NOSs) requires calmodulin binding and is associated with increased NO synthesis NADPH oxidation (Abu-Soud, H. M., Stuehr, D. J. (1993) Proc. Natl. Acad. Sci., U. S. A. 90, 10769-10772). Here, we examined how L-arginine analogs N omega-methyl-L-arginine (NMA), omega-nitro-L-arginine methyl ester (NAME), d-(thioureido)-L-norvaline (thiocitrulline) affect electron flux through neuronal macrophage NOS. L-Arginine NMA or decreased NOS consumption...
Myeloperoxidase (MPO) catalyzes the formation of potent oxidants that have been implicated in pathogenesis various diseases including atherosclerosis, asthma, arthritis, and cancer. Melatonin plays an important part regulation body functions circadian sleep rhythms, blood pressure, oncogenesis, retinal function, seasonal reproduction, immunity. Here, we demonstrate melatonin serves as a inhibitor MPO under physiological-like conditions. In presence chloride (Cl-), inactivated at two points...
We studied steps that make up the initial and steady-state phases of nitric oxide (NO) synthesis to understand how activity bovine endothelial NO synthase (eNOS) is regulated. Stopped-flow analysis NADPH-dependent flavin reduction showed rate increased from 0.13 86 s−1 upon calmodulin binding, but this supported slow heme in presence either Arg orN ω-hydroxy-l-arginine (0.005 0.014 s−1, respectively, at 10 °C). O2binding ferrous eNOS generated a transient dioxy species (Soret peak 427 nm)...