Disease relevance of hydroxylamine

• The time-resolved operation of the Escherichia coli ferric enterobactin receptor FepA was observed in vivo with electron spin resonance spectroscopy by monitoring the mobility of covalently bound nitroxide spin labels [1].
• In addition, we report a N-tert-butyl-alpha-phenylnitrone-dependent nitroxide radical obtained in the lipid fraction of the ischemia/reperfusion-lesioned brains, but there was very little radical present in the comparable sham-operated control brains [2].
• TEMPO slowed the heart rate, but compensatory pacing did not alter the dramatic effect of the nitroxide on reperfusion arrhythmia [3].
• We previously demonstrated that the nitroxide antioxidant tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) increased latency to tumorigenesis and doubled (100%) the lifespan of Atm-deficient mice, a mouse model of ataxia telangiectasia, which displays accelerated oxidative damage and stress [4].
• In addition, this nitroxide lowered weight gain of tumor prone mice without changes in food intake, metabolism or activity level and exhibited an anti-proliferative effect in vitro [5].

Psychiatry related information on hydroxylamine

• The spin-label probe 5-SASL (stearic acid spin-label with nitroxide free radical in position 5 of hydrocarbon chain), detectable by electron spin resonance (ESR), was tested to evaluate pH and reaction time dependencies of hydrophobic interactions with humic acid (HA) [6].

High impact information on hydroxylamine

• We provide a review of current electron spin resonance (ESR) techniques for studying basic molecular mechanisms in membranes and proteins by using nitroxide spin labels [7].
• At added LF levels ranging from 4 to 15 micrograms/10(7) PMN there was a dose-dependent reduction in PMN surface charge reaching 4 mV, when the partitioning into the membrane of a charged amphipathic nitroxide spin label was measured by electron spin resonance spectroscopy, whereas transferrin was without effect [8].
• Erythrocytes were labeled with the nitroxide-substituted analogue of stearic acid, 2-(3-carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl, and ESR spectra were obtained [9].
• To identify sites in arrestin involved in receptor interaction, a nitroxide-containing side chain was introduced at each of 28 different positions in visual arrestin, and the dynamics of the side chain was used to monitor arrestin interaction with phosphorylated forms of its cognate receptor, rhodopsin [10].
• Derivatives of monomeric PLB were synthesized, each of which contained a single spin-labeled 2,2,6,6,-Tetramethyl-piperidine-N-oxyl-4-amino-4-carboxylic acid amino acid, with the nitroxide-containing ring covalently and rigidly attached to the alpha-carbon, providing direct insight into the conformational dynamics of the peptide backbone [11].

Chemical compound and disease context of hydroxylamine

• Hydroxylamine oxidoreductase from Nitrosomonas europeae catalyzes the oxidative conversion of NH2OH to NO-2 [12].
• Twenty-four mutants, each containing a single free cysteine substituted for an amino acid in the COX-2 membrane binding domain were expressed using the baculovirus system and purified, then conjugated with a nitroxide spin label and reconstituted into liposomes [13].
• In the present study, we assessed the effects of Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, TPL), a piperidine nitroxide with growth-inhibitory properties in tumor cell lines, on a number of molecular mechanisms involved in the resistance of human breast adenocarcinoma cell lines to doxorubicin (DOX) [14].
• Base dynamics of nitroxide-labeled thymidine analogues incorporated into (dA-dT)n by DNA polymerase I from Escherichia coli [15].
• OBJECTIVE: To examine the effects of nebivolol, a beta-blocker with nitroxide-mediated vasodilating properties, on coronary flow reserve (CFR) in patients with uncomplicated arterial hypertension [16].

Biological context of hydroxylamine

• A weak dipolar interaction is detected between the nitroxide and paramagnetic transition ions, indicating this position is approximately 19 A from the nearest high affinity binding site [17].
• Direct measurement of nitroxide pharmacokinetics in isolated hearts situated in a low-frequency electron spin resonance spectrometer: implications for spin trapping and in vivo oxymetry [18].
• PSTV was inactivated by ribonuclease digestion, psoralen photoadduct formation, Zn2+ -catalyzed hydrolysis, and chemical modification with NH2OH [19].
• The use of molecular genetics to introduce both a metal ion binding site and a nitroxide spin label into the same protein opens the use of paramagnetic metalnitroxyl interactions to estimate intramolecular distances in a wide variety of proteins [20].
• Analysis of the orientation-dependent information thus obtained has clearly shown that the lignad moieties in all 4 respective complexes are accommodated in adjacent base-pair layers of the DNA with the nitroxide reporter oriented in 1 preferential direction [21].

Anatomical context of hydroxylamine

• Surface localization of sites of reduction of nitroxide spin-labeled molecules in mitochondria [22].
• In the absence of exogenous iron, no nitroxide was observed, providing evidence for the lack of the endogenous capacity of neutrophils, monocytes, and MDM to generate .OH [23].
• Treatment of rod outer segment membranes (prepared from rat retinas previously labeled in vivo with [3H]palmitate) with 1 M NH2OH typically removed greater than or equal to 75% of the [3H]palmitate initially bound to rhodopsin [24].
• Nitroxide radical attenuates ischaemia/reperfusion injury to the rat small intestine [25].
• Nitroxide metabolism in the human keratinocyte cell line HaCaT [26].

Associations of hydroxylamine with other chemical compounds

• To investigate the interaction of HA with membranes, two 40-residue, cysteine-substituted peptides comprising the loop region and the first part of the coiled-coil stem were synthesized and modified with a nitroxide spin label [27].
• To characterize the mechanism by which receptors propagate conformational changes across membranes, nitroxide spin labels were attached at strategic positions in the bacterial aspartate receptor [28].
• The results indicate that the dismutation of .O2- is catalyzed by the oxoammonium/nitroxide redox couple for carbocyclic nitroxide derivatives [29].
• The high-field EPR spectra from random dispersions of the cholesterol-containing membranes display very little axial averaging of the nitroxide g-tensor anisotropy for lipids spin labeled toward the carboxyl end of the sn-2 chain (down to the 8-C atom) [30].
• Thiouridine at position 8 (s4U8) of tRNAf1Met was spin-labeled with the nitroxide free radical, N-(1-oxyl-2,2,5,5-Tetramethyl-3-pyrrolidinyl) bromacetamide, for proton nuclear magnetic resonance spectroscopic studies [31].

Gene context of hydroxylamine

• We tested this hypothesis by determining whether the well-described nitroxide antioxidant, tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl), acts as a chemopreventative agent in Atm mutant mice, a model of the human cancer prone syndrome ataxia-telangiectasia [5].
• Line shape broadening resulting from spin-spin coupling of nitroxide pairs introduced into the membrane-binding helices of PGHS-2 was used to calculate the inter-helical distances and changes in these distances that occur in response to binding various ligands [32].
• The nitroxide tempol induces oxidative stress, p21(WAF1/CIP1), and cell death in HL60 cells [33].
• The antiproliferative effect of Tempol, a stable nitroxide free radical, was investigated on the p53-negative human leukemia cell line HL60 [33].
• The determination of the NMR structure of the sterol carrier protein-2 (SCP2), analysis of backbone (15)N spin relaxation parameters and NMR studies of nitroxide spin-labeled substrate binding are presented as a new basis for investigations of the mode of action of SCP2 [34].

Analytical, diagnostic and therapeutic context of hydroxylamine

• The boundaries and structures of membrane-embedded domains in integral membrane proteins can be determined by a method based on a combination of site-specific mutagenesis and nitroxide spin labeling [35].
• Time domain pulsed saturation recovery and electron-electron double resonance spectroscopies were used to measure the spin-lattice relaxation rates of the electron and the nitrogen nucleus in nitroxide spin labels in liquids [36].
• Cardiac reperfusion damage prevented by a nitroxide free radical [3].
• Specific IgG antibodies directed against the spin-label nitroxide group present as a lipid hapten in single-compartment lipid vesicles have been visualized by using freeze-etch electron microscopy [37].
• Experiments were performed using low-frequency (1.3 GHz) in vivo EPR spectroscopy and imaging techniques with a nitroxide redox probe [38].

References