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Find video protocols related to scientific articles indexed in Pubmed.
Prognostic role of HER2 expression in bladder cancer: a systematic review and meta-analysis.
Int Urol Nephrol
PUBLISHED: 09-19-2014
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The prognostic role of human epidermal growth factor receptor 2 (HER2) in bladder cancer (BCa) remains controversial. Thus, we conducted a meta-analysis to assess the prognostic significance of HER2 for patients with BCa.
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Intracranial Stents Past, Present and the Future Trend: Stents Made with Nano-particle or Nanocomposite Biomaterials.
Curr. Med. Chem.
PUBLISHED: 05-26-2014
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Stroke or cerebral vascular accidents are among the leading causes of death in the world. With the availability of Digital Subtraction Angiography, transluminal angioplasty has become feasible in many situations and the role of intracranial stents is becoming ever more important in the management of cerebral vascular diseases. In current review, we outline the chronological development of various stents namely; balloon expandable stent, self-expandable open cell stent, self-expandable close cell stent and the flow diverting stent. Further we discuss their advantages and limitations in terms of stent migration, thromboemboli, damage to vessels during procedure, in-stent stenosis and hyper-perfusion damage. We also discuss the importance of in-situ endothelialization, controlled expandability and hemodynamic manipulation in stent design. Further, we summarized the role and need for further development in the areas of bio-compatible materials, endothelial progenitor cell capture technique, bio-functionalized-magnetic-nano-particles and nanotechnology which are significant in intracranial stent development.
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MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.
J. Exp. Med.
PUBLISHED: 04-21-2014
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Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.
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A model for the flexibility of the distal histidine in dehaloperoxidase-hemoglobin A based on X-ray crystal structures of the carbon monoxide adduct.
Biochemistry
PUBLISHED: 04-08-2014
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Dehaloperoxidase hemoglobin A (DHP A) is a multifunctional hemoglobin that appears to have evolved oxidative pathways for the degradation of xenobiotics as a protective function that complements the oxygen transport function. DHP A possesses at least two internal binding sites, one for substrates and one for inhibitors, which include various halogenated phenols and indoles. Herein, we report the X-ray crystallographic structure of the carbonmonoxy complex (DHPCO). Unlike other DHP structures with 6-coordinated heme, the conformation of the distal histidine (H55) in DHPCO is primarily external or solvent exposed, despite the fact that the heme Fe is 6-coordinated. As observed generally in globins, DHP exhibits two distal histidine conformations (one internal and one external). In previous structural studies, we have shown that the distribution of H55 conformations is weighted strongly toward the external position when the DHP heme Fe is 5-coordinated. The large population of the external conformation of the distal histidine observed in DHPCO crystals at pH 6.0 indicates that some structural factor in DHP must account for the difference from other globins, which exhibit a significant external conformation only when pH < 4.5. While the original hypothesis suggested that interaction with a heme-Fe-bound ligand was the determinant of H55 conformation, the current study forces a refinement of that hypothesis. The external or open conformation of H55 is observed to have interactions with two propionate groups in heme, at distances of 3.82 and 2.73 Å, respectively. A relatively weak hydrogen bonding interaction between H55 and CO, combined with strong interactions with heme propionate (position 6), is hypothesized to strengthen the external conformation of H55. Density function theory (DFT) calculations were conducted to test whether there is a weaker hydrogen bond interaction between H55 and heme bonded CO or O2. Molecular dynamics simulations were conducted to examine how the tautomeric forms of H55 affect the dynamic motions of the distal histidine that govern the switching between open and closed conformations. The calculations support the modified hypothesis suggesting a competition between the strength of interactions with heme ligand and the heme propionates as the factors that determine the conformation of the distal histidine.
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Genome-wide study reveals an important role of spontaneous autoimmunity, cardiomyocyte differentiation defect and anti-angiogenic activities in gender-specific gene expression in Keshan disease.
Chin. Med. J.
PUBLISHED: 01-04-2014
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Keshan disease (KD) is an endemic cardiomyopathy in China. The etiology of KD is still under debate and there is no effective approach to preventing and curing this disease. Young women of child-bearing age are the most frequent victims in rural areas. The aim of this study was to determine the differences between molecular pathogenic mechanisms in male and female KD sufferers.
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Decreased MicroRNA-125a-3p Contributes to Upregulation of p38 MAPK in Rat Trigeminal Ganglions with Orofacial Inflammatory Pain.
PLoS ONE
PUBLISHED: 01-01-2014
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Orofacial inflammatory pain is a difficult clinical problem, and the specific molecular mechanisms for this pain remain largely unexplained. The present study aimed to determine the differential expression of microRNAs (miRNAs) and disclose the underlying role of miR-125a-3p in orofacial inflammatory pain induced by complete Freund's adjuvant (CFA). Thirty-two differentially expressed miRNAs were first screened using a microarray chip in ipsilateral trigeminal ganglions (TGs) following CFA injection into the orofacial skin innervated by trigeminal nerve, and a portion of them, including miR-23a*, -24-2*, -26a, -92a, -125a-3p, -183 and -299 were subsequently selected and validated by qPCR. The target genes were predicted based on the miRWalk website and were further analyzed by gene ontology (GO). Further studies revealed miR-125a-3p expression was down-regulated, whereas both the expression of p38 MAPK (mitogen-activated protein kinase) alpha and CGRP (calcitonin gene-related peptide) were up-regulated in ipsilateral TGs at different time points after CFA injection compared with control. Furthermore, mechanistic study revealed that miR-125a-3p negatively regulates p38 alpha gene expression and is positively correlated with the head withdrawal threshold reflecting pain. Luciferase assay showed that binding of miR-125a-3p to the 3'UTR of p38 alpha gene suppressed the transcriptional activity, and overexpression of miR-125a-3p significantly inhibited the p38 alpha mRNA level in ND8/34 cells. Taken together, our results show that miR-125a-3p is negatively correlated with the development and maintenance of orofacial inflammatory pain via regulating p38 MAPK.
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Laparoscopic versus open radical cystectomy for elderly patients over 75-year-old: a single center comparative analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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To explore the morbidity, mortality and oncological results of laparoscopic radical cystectomy (LRC) in the elderly patients over 75-year-old in contrast with open radical cystectomy (ORC).
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The Regulatory Implications of Hydroquinone for the Multifunctional Enzyme Dehaloperoxidase-Hemoglobin from Amphitrite ornata.
J Phys Chem B
PUBLISHED: 11-18-2013
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Hydroquinone (H2Q) has been observed to compete with the oxidation of substrates 2,4,6-tribromophenol (2,4,6-TBP) and 2,4,6-trichlorophenol (2,4,6-TCP) catalyzed by the dehaloperoxidase-hemoglobin (DHP) from Amphitrite ornata in the presence of H2O2. This competition is observed as a lag phase during which H2Q is preferentially oxidized to 1,4-benzoquinone (1,4-BQ) while totally inhibiting either 2,4,6-TBP or 2,4,6-TCP oxidation. The inhibition by H2Q is distinct from that of the native competitive inhibitor 4-bromophenol (4-BP) since H2Q is itself oxidized and its product 1,4-BQ is not an inhibitor. Thus, once H2Q is completely consumed, the inhibition is removed, and normal substrate turnover is initiated, which explains the lag phase. To probe the mechanism of lag phase, the reactions between H2Q and DHP were both studied both in the presence and in the absence of H2O2. The reversible reactions between ferric/oxyferrous DHP A and H2Q/1,4-BQ are shown to involve a proton-coupled electron transfer (PCET) mechanism, where the distal histidine His(55) serves as the proton acceptor. The pKa of the distal histidine His(55) has been determined by resonance Raman spectroscopy in order to corroborate its involvement in this mechanism. Consistent with the proposed mechanism, kinetic assays have shown that H2Q serves as a substrate for DHP that follows the Michaelis-Menten kinetics. Unlike H2Q, the product 1,4-BQ has a relatively large Ki value and therefore has negligible inhibition. This study sheds light on understanding the difference between substrate and inhibitor binding sites and regulatory implication for the peroxidase and oxygen-transporter functions in DHP. It also provides information on PCET in DHP, which is important for resolving the switching between the ferric peroxidase catalytic function and the ferrous oxygen transport function.
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Functional consequences of the open distal pocket of dehaloperoxidase-hemoglobin observed by time-resolved X-ray crystallography.
Biochemistry
PUBLISHED: 10-28-2013
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Using time-resolved X-ray crystallography, we contrast a bifunctional dehaloperoxidase-hemoglobin (DHP) with previously studied examples of myoglobin and hemoglobin to understand the functional role of the distal pocket of globins. One key functional difference between DHP and other globins is the requirement that H2O2 enter the distal pocket of oxyferrous DHP to displace O2 from the heme Fe atom and thereby activate the heme for the peroxidase function. The open architecture of DHP permits more than one molecule to simultaneously enter the distal pocket of the protein above the heme to facilitate the unique peroxidase cycle starting from the oxyferrous state. The time-resolved X-ray data show that the distal pocket of DHP lacks a protein valve found in the two other globins that have been studied previously. The photolyzed CO ligand trajectory in DHP does not have a docking site; rather, the CO moves immediately to the Xe-binding site. From there, CO can escape but can also recombine an order of magnitude more rapidly than in other globins. The contrast with DHP dynamics and function more precisely defines the functional role of the multiple conformational states of myoglobin. Taken together with the high reduction potential of DHP, the open distal site helps to explain how a globin can also function as a peroxidase.
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Act1 mediates IL-17-induced EAE pathogenesis selectively in NG2+ glial cells.
Nat. Neurosci.
PUBLISHED: 07-10-2013
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Interleukin 17 (IL-17) is a signature cytokine of Th17 cells. We previously reported that deletion of NF-?B activator 1 (Act1), the key transducer of IL-17 receptor signaling, from the neuroectodermal lineage in mice (neurons, oligodendrocytes and astrocytes) results in attenuated severity of experimental autoimmune encephalomyelitis (EAE). Here we examined the cellular basis of this observation. EAE disease course was unaffected by deletion of Act1 in neurons or mature oligodendrocytes, and Act1 deletion in astrocytes only modestly affected disease course. Deletion of Act1 in NG2(+) glia resulted in markedly reduced EAE severity. Furthermore, IL-17 induced characteristic inflammatory mediator expression in NG2(+) glial cells. IL-17 also exhibited strong inhibitory effects on the maturation of oligodendrocyte lineage cells in vitro and reduced their survival. These data identify NG2(+) glia as the major CNS cellular target of IL-17 in EAE. The sensitivity of oligodendrocyte lineage cells to IL-17-mediated toxicity further suggests a direct link between inflammation and neurodegeneration in multiple sclerosis.
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EETs and CYP2J2 inhibit TNF-?-induced apoptosis in pulmonary artery endothelial cells and TGF-?1-induced migration in pulmonary artery smooth muscle cells.
Int. J. Mol. Med.
PUBLISHED: 03-27-2013
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Cytochrome P450 epoxygenase-derived epoxyeicosatrienoic acids (EETs) have multiple biological functions in cardiovascular homeostasis. The antiin?ammatory, anti-migratory and pro-proliferative effects of EETs suggest a possible bene?cial role for EETs in the apoptosis, proliferation and migration of pulmonary vascular cells. In this study, we investigated the effects of exogenous EETs and cytochrome P450 2J2 (CYP2J2) overexpression on tumor necrosis factor-? (TNF-?)-induced pulmonary artery endothelial cell (PAEC) apoptosis, and transforming growth factor-?1 (TGF-?1)-induced pulmonary artery smooth muscle cell (PASMC) proliferation and migration. PAECs and PASMCs were cultured from porcine pulmonary arteries. Our findings indicated that EETs or CYP2J2 overexpression signi?cantly protected the PAECs from TNF-?-induced apoptosis, as evaluated by cell viability and flow cytometry. Two mechanisms were found to be involved in these important protective effects: firstly, EETs and CYP2J2 overexpression inhibited the decrease in the expression of the antiapoptotic proteins, Bcl-2 and Bcl-xL, as well as the increase in the expression of the pro-apoptotic protein, Bax, mediated by TNF-?; secondly, they activated the phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) signaling pathways. We also found that 11,12-EET and 14,15-EET significantly inhibited TGF-?1-stimulated PASMC migration. However, EETs did not suppress TGF-?1-induced PASMC proliferation in vitro. These data may represent a novel approach to mitigate pulmonary vascular remodeling in diseases, such as pulmonary arterial hypertension.
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Structural and kinetic study of an internal substrate binding site in dehaloperoxidase-hemoglobin A from Amphitrite ornata.
Biochemistry
PUBLISHED: 03-26-2013
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X-ray crystal structures of dehaloperoxidase-hemoglobin A (DHP A) from Amphitrite ornata soaked with substrate, 2,4,6-tribromophenol (2,4,6-TBP), in buffer solvent with added methanol (MeOH), 2-propanol (2-PrOH), and dimethyl sulfoxide (DMSO) reveal an internal substrate binding site deep in the distal pocket above the ?-edge of the heme that is distinct from the previously determined internal inhibitor binding site. The peroxidase function of DHP A has most often been studied using 2,4,6-trichlorophenol (2,4,6-TCP) as a substrate analogue because of the low solubility of 2,4,6-TBP in an aqueous buffer solution. Previous studies at low substrate concentrations pointed to the binding of substrate 2,4,6-TCP at an external site near the exterior heme ?- or ?-edge as observed in the class of heme peroxidases. Here we report that the turnover frequencies of both substrates 2,4,6-TCP and 2,4,6-TBP deviate from Michaelis-Menten kinetics at high concentrations. The turnover frequency reaches a maximum in the range of 1400-1700 ?M, with a decrease in rate at higher concentrations that is both substrate- and solvent-dependent. The X-ray crystal structure is consistent with the presence of an internal active site above the heme ?-edge, in which the substrate would be oxidized in two consecutive steps inside the enzyme, followed by attack by H2O via a water channel in the protein. The physiological role of the internal site may involve interactions with any of a number of aromatic toxins found in benthic ecosystems where A. ornata resides.
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Minimally invasive surgery for patients with bulky bladder stones and large benign prostatic hyperplasia simultaneously: a novel design.
Urol. Int.
PUBLISHED: 02-21-2013
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To determine the efficacy and safety of a novel minimally invasive design for treating bulky vesical calculi and large benign prostatic hyperplasia (BPH) simultaneously.
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Increased expression of EphA7 in inflamed human dental pulp.
J Endod
PUBLISHED: 01-17-2013
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Pulpitis has been associated with abundant inflammatory cells, dilated blood vessels, and thickening nerve fibers histopathologically with or without severe pain clinically. On the basis of EphA7 receptor expression in inflammatory cells, the developing mouse dental pulp, and trigeminal nerve system, EphA7 may possibly be involved in local inflammatory response and sensory innervation of adult dental pulp as well as odontogenic pain conducted through the trigeminal system. The purpose of the study was to analyze the expression of EphA7 gene in healthy and inflamed human dental pulps and to elucidate the roles of EphA7 gene in dental pulp inflammation response and odontogenic pain.
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Bradykinin Inhibits Oxidative Stress-Induced Cardiomyocytes Senescence via Regulating Redox State.
PLoS ONE
PUBLISHED: 01-01-2013
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Cell senescence is central to a large body of age related pathology, and accordingly, cardiomyocytes senescence is involved in many age related cardiovascular diseases. In consideration of that, delaying cardiomyocytes senescence is of great importance to control clinical cardiovascular diseases. Previous study indicated that bradykinin (BK) protected endothelial cells from senescence induced by oxidative stress. However, the effects of bradykinin on cardiomyocytes senescence remain to be elucidated. In this study, we investigated the effect of bradykinin on H2O2-induced H9C2 cells senescence.
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Oleate blocks palmitate-induced abnormal lipid distribution, endoplasmic reticulum expansion and stress, and insulin resistance in skeletal muscle.
Endocrinology
PUBLISHED: 04-19-2011
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Pathological elevation of plasma fatty acids reduces insulin sensitivity. Although several regulation pathways have been reported, the molecular mechanisms of insulin sensitivity remain elusive, especially in skeletal muscle where most glucose is consumed. This study focuses on how two major dietary fatty acids affect insulin signaling in skeletal muscle cells. Palmitic acid (PA) not only reduced insulin-stimulated phosphorylation of Akt but also induced endoplasmic reticulum (ER) expansion and ER stress. Relieving ER stress using 4-phenyl butyric acid blocked PA-mediated protein kinase R-like ER kinase phosphorylation and ER expansion and reversed the inhibitory effect of PA on insulin-stimulated Akt phosphorylation. Importantly, oleic acid (OA) could also recover PA-reduced Akt phosphorylation and abolish both PA-mediated ER expansion and ER stress. The competition between these two fatty acids was further verified in rat skeletal muscle using venous fatty acid infusion. (3)H-labeled PA was converted mainly to active lipids (phospholipids and diacylglycerol) in the absence of OA, but to triacylglycerol in the presence of OA. Subcellular triacylglycerol and adipocyte differentiation-related protein from PA-treated cells cofractionated with the ER in the absence of OA but switched to the low-density fraction in the presence of OA. Taken together, these data suggest that the PA-mediated lipid composition and localization may cause ER expansion and consequently cause ER stress and insulin resistance in skeletal muscle.
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Mixed-type total anomalous pulmonary venous connection in an adult.
Ann. Thorac. Surg.
PUBLISHED: 01-25-2011
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Cardiac plus infracardiac mixed-type total anomalous pulmonary venous connection is an extremely rare congenital heart disease. We describe a case in which the pulmonary veins made a confluence and connected to a vertical vein running into the inferior vena cava by the way of the hepatic vein. Surgical correction was successfully obtained by deroofing the coronary sinus and using the pericardial patch to reconstruct the interatrial septum. The patient showed no signs of any complication at her 5-month follow-up.
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SIGIRR, a negative regulator of colon tumorigenesis.
Drug Discov Today Dis Mech
PUBLISHED: 01-01-2011
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Inappropriate activation of the Toll-IL-1R (TL-IL-1) signaling by commensal bacteria contributes to the pathogenesis of inflammatory bowel diseases and colitis-associated cancer. Recent studies have identified SIGIRR as a negative regulator of TL-IL-1 signaling. It dampens intestinal inflammation and tumorigenesis in the colon. In this review, we will discuss the role of SIGIRR in different cell types and the mechanisms underlying its tumor suppressor function.
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Intragastric administration of evodiamine suppresses NPY and AgRP gene expression in the hypothalamus and decreases food intake in rats.
Brain Res.
PUBLISHED: 02-20-2009
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Evodiamine (Evo), an alkaloidal component extracted from the fruit of Evodiae fructus (Evodia rutaecarpa Bentham, Rutaceae), decreases the body weight of rats through a poorly defined mechanism. The hypothalamus is one of the areas in the brain linked to the control of food intake and energy expenditure. We postulate that Evo mediates this activity by modulating feeding-related peptides in the hypothalamus. We investigated the effects of Evo on food intake, body weight, the mRNA expression and peptide level of feeding-related peptides in the hypothalamus, in male rats. The juvenile rats of 5 weeks old were used at the start of the experiment. Evo (40 mg/kg or 4 mg/kg) was administered intragastrically for 25 days, and food intake and body weight of rats were recorded daily. Blood samples were collected for leptin radioimmunoassay (RIA). Real-Time PCR was used to analyze the mRNA expression. Western Blotting and immunohistochemistry were used to analyze the peptide. Our results show that intragastric administration of Evo (40 mg/kg) decreased rate of food intake and body weight increase following rat growth, reduced orexigenic neuropeptide Y (NPY) and agouti-gene related protein (AgRP) mRNA levels and NPY peptide level in the arcuate nucleus (ARC) of the hypothalamus, but it increases the circulating level of leptin. Intragastric administration of a smaller dose of Evo (4 mg/kg) was ineffective. These data suggest that Evo decreases food intake, and therefore body weight, partly by down-regulating NPY and AgRP mRNA expression and peptide expression in the ARC of the hypothalamus.
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Catalytic efficiency of dehaloperoxidase A is controlled by electrostatics--application of the vibrational Stark effect to understand enzyme kinetics.
Biochem. Biophys. Res. Commun.
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The vibrational Stark effect is gaining popularity as a method for probing electric fields in proteins. In this work, we employ it to explain the effect of single charge mutations in dehaloperoxidase-hemoglobin A (DHP A) on the kinetics of the enzyme. In a previous communication published in this journal (BBRC 2012, 420, 733-737) it has been shown that an increase in the overall negative charge of DHP A through mutation causes a decrease in its catalytic efficiency. Here, by labeling the protein with 4-mercaptobenzonitrile (MBN), a Stark probe molecule, we provide further evidence that the diffusion control of the catalytic process arises from the electrostatic repulsion between the enzyme and the negatively charged substrate. The linear correlation observed between the nitrile stretching frequency of the protein-bound MBN and the catalytic efficiency of the single-site mutants of the enzyme indicates that electrostatic interactions play a dominant role in determining the catalytic efficiency of DHP A.
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The role of the distal histidine in H2O2 activation and heme protection in both peroxidase and globin functions.
J Phys Chem B
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The distal histidine mutations of dehaloperoxidase-hemoglobin A (DHP A) to aspartate (H55D) and asparagine (H55N) have been prepared to study the role played by the distal histidine in both activation and protection against oxidation by radicals in heme proteins. The H55D and H55N mutants of DHP A have ~6-fold and ~11-fold lower peroxidase activities than wild type enzyme toward the oxidation of 2,4,6-trichlorophenol (TCP) to yield 2,6-dichloroquinone (DCQ) in the presence of H(2)O(2). The origin of the lower rate constants may be the solvent-exposed conformations of distal D55 and N55, which would have the dual effect of destabilizing the binding of H(2)O(2) to the heme iron, and of removing the acid-base catalyst necessary for the heterolytic O-O bond cleavage of heme-bound H(2)O(2) (i.e., compound 0). The partial peroxidase activity of H55D can be explained if one considers that there are two conformations of the distal aspartate (open and closed) by analogy with the distal histidine. We hypothesize that the distal aspartate has an active conformation in the distal pocket (closed). Although the open form is observed in the low-temperature X-ray crystal structure of ferric H55D, the closed form is observed in the FTIR spectrum of the carbonmonoxy form of the H55D mutant. Consistent with this model, the H55D mutant also shows inhibition of TCP oxidation by 4-bromophenol (4-BP). Consistent with the protection hypothesis, compound ES, the tyrosyl radical-containing ferryl intermediate observed in WT DHP A, was not observed in H55D.
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Study of the electrostatic effects of mutations on the surface of dehaloperoxidase-hemoglobin A.
Biochem. Biophys. Res. Commun.
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Point mutations of dehaloperoxidase-hemoglobin A (DHP A) that affect the surface charge have been prepared to study the interaction between DHP A with its substrate 2,4,6-trichlorophenol (TCP). Kinetic studies of these surface mutations showed a correlation, in which the more positively charged mutants have increased catalytic efficiency compared with wild type DHP A. As a result, the hypothesis of this study is that there is a global electrostatic interaction between DHP A and TCP. The electrostatic nature of substrate binding was further confirmed by the result that kinetic assays of DHP A were affected by ionic strength. Furthermore, isoelectric focusing (IEF) gel study showed that the pI-6.8 for DHP A, which indicates that DHP A has a slight negative charge pH 7, consistent with the kinetic observations.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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