Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.9 (glucose-6-phosphatase)
 3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study an attempt has been made to evaluate the effect of Tiron along with Zinc, Selenium and Vitamin E against vanadium intoxication in female albino rats. Toxicant caused significant increase in the activities of serum transaminases, serum alkaline phosphatase and lactate dehydrogenase. Significant decrease was observed in blood sugar, serum albumin and triglyceride levels whereas serum proteins, cholesterol and urea levels increased significantly during toxicity (p </= 0.001). Hepatic lipid peroxidation increased significantly, whereas significant depletion was observed in reduced glutathione after vanadium administration. The activity of glucose-6-phosphatase in the liver was also inhibited significantly after vanadium administration. A significant rise was observed in glycogen content of liver and kidney after toxicant exposure. Activities of alkaline phosphatase, adenosine triphosphatase and succinic dehydrogenase were inhibited significantly on the contrary activity of acid phosphatase elevated in kidney. Histopathological examination of the liver and kidney using light and ultramicroscopic study also substantiated the above findings. It was found that therapy with Tiron was effective but significant recovery in all the parameters was found with Tiron + Se followed by Tiron+ VitE and Tiron +Zn.
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PMID:Effect of tiron and its combination with nutritional supplements against vanadium intoxication in female albino rats. 1753 42

Bis(allixinato)oxovanadium(IV), VO(alx)(2) (alx is 3-hydroxy-5-methoxy-6-methyl-2-pentyl-4-pyrone), has been reported to act as an antidiabetic agent in streptozotocin-induced type-1-like and obesity-linked KKA(y) type 2 diabetic model mice. VO(alx)(2) is also proposed as a candidate agent for treating metabolic syndromes in animals. However, its functional mechanism is yet to be clarified. In this study, we examined whether VO(alx)(2) contributes to both the activation of the insulin signaling cascade that activates glucose transporter 4 (GLUT4) translocation and the regulation of the forkhead box O1 (FoxO1) transcription factor that controls the gene transcription of gluconeogenesis genes. The following three important results were obtained: (1) intracellular vanadium concentration in 3T3-L1 adipocytes is higher after treatment with VO(alx)(2) than with VOSO(4); (2) VO(alx)(2) stimulates the translocation of GLUT4 to the plasma membrane following activation of the tyrosine phosphorylation of the insulin receptor beta-subunit (IRbeta) and insulin receptor substrate (IRS) as well as Akt kinase in 3T3-L1 adipocytes; and (3) the mechanism of inhibition of glucose-6-phosphatase (G6Pase) catalytic subunit gene expression by vanadium is due to disruption of FoxO1 binding with the G6Pase promoter, which indicates that FoxO1 is phosphorylated by VO(alx)(2)-stimulated Akt in HepG2 cells. On the basis of these results, we propose that the critical functions of VO(alx)(2) involve the activation of phosphatidylinositol 3-kinase-Akt signaling through the enhancement of tyrosine phosphorylation of IRbeta and IRS, which in turn transmits the signal to activate GLUT4 translocation, and the regulation of the DNA binding activity of the FoxO1 transcription factor.
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PMID:Action mechanism of bis(allixinato)oxovanadium(IV) as a novel potent insulin-mimetic complex: regulation of GLUT4 translocation and FoxO1 transcription factor. 1780 85

The crystal structure of the apo form of vanadium chloroperoxidase from Curvularia inaequalis reacted with para-nitrophenylphosphate was determined at a resolution of 1.5 A. The aim of this study was to solve structural details of the dephosphorylation reaction catalyzed by this enzyme. Since the chloroperoxidase is functionally and evolutionary related to several acid phosphatases including human glucose-6-phosphatase and a group of membrane-bound lipid phosphatases, the structure sheds light on the details of the dephosphorylation catalyzed by these enzymes as well. The trapped intermediate found is bound to the active site as a metaphosphate anion PO3-, with its phosphorus atom covalently attached to the Nepsilon2 atom of His496. An apical water molecule is within hydrogen-bonding distance to the phosphorus atom of the metaphosphate, and it is in a perfect position for a nucleophilic attack on the metaphosphate-histidine intermediate to form the inorganic phosphate. This is, to our knowledge, the first structural characterization of a real reaction intermediate of the inorganic phosphate group release in a dephosphorylation reaction.
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PMID:Crystal structure of a trapped phosphate intermediate in vanadium apochloroperoxidase catalyzing a dephosphorylation reaction. 1816 51

Structural and functional analogies between acid phosphatases and vanadium haloperoxidases are reflected in the conservation of the amino acid residues contributing to the active sites of these enzymes. This has interesting consequences for the research on both enzyme systems. A first example is the newly proposed structure for the active site of human glucose-6-phosphatase: The picture shows parts of six of the nine transmembrane helices as well as the amino acids (black ovals) that presumably participate in the formation of the active site.
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PMID:Phosphate and Vanadate in Biological Systems: Chemical Relatives or More? 2971 69


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