Tuesday, March 03, 2015

Thioredoxin reductase: Selenotetrapeptide sequences with specificity for thioredoxin and glutathione systems

  Thioredoxin reductase (EC TXNRD1 (Alternate Symbols: GRIM-12, TR, TRXR) chromosomal position 12q23.3-q24.1 (§, ) is a homodimeric selenocysteine-containing enzyme. Secys a selenocysteine residue is an essential TR isozyme component, located near the C-terminus region [cysteine (Cys)-497,Secys-498] of the intracellular, redox cellular environments center in the catalytically active enzyme site, Gly-499 is the actual C-terminal amino acid. In their N-terminal sequences Cys-59, Cys-64 links the thiol/disulfide oxidoreductase dependent pathway reductases from there to the flexible C-terminal part (Secys) of the other sub cellular subunit by which Selenocystine is efficiently reduced and induce RNR (Ribonucleotide reductase) for replication and repair, where Trx reductase (TR) or oxidized GSH (GSSG) reductase further supply electrons for RNR. The protein reversibly modulates specific signal transduction cascades, to regulate multiple downstream intracellular redox-sensitive proteins that links NADPH and thiol-dependent processes which catalyzes NADPH-dependent reduction in the presence of the redox protein-Trx and thioredoxin reductase (TR) maintain cysteine residues in numerous proteins in the reduced state. There are three TXNRD selenoproteins  5-prime end variants essential for mammals, one V3 (TXNRD1) encodes an N-terminal glutaredoxin (GRX) these variants code for thioredoxin glutathione reductases (TGR). V3 associates with and triggers formation of Filopodia (cytoplasmic filaments) can guide actin in migrating cells, the emerging protrusions of cell membrane restructuring involved is in 'deglutathionylation values" for mitochondrial and cytosolic thioredoxin reductase (TR) domains. Characterization of the TR native Thioredoxin and glutathione systems (TGR) suggests that the lifecycle of E. granulosus and Schistosoma mansoni a phylum of Platyhelmintha, involves the TXNRD1_v3 isoform containing a fused (Grx) glutaredoxin domain which is abolished by deglutathionylation' targeted to either mitochondria or the nucleus in the reduction of glutathionylated substrates, in leishmaniasis (disease) glutathione reductase system (TGR) is replaced by the trypanothione reductase (TcTR) system in mammalian cells, essential as these TR3 are significant as a recognized drug target of these (TcTR) human protozoan parasites. Cytosolic TR1, mitochondrial - TR3 and TrxR2 (locus 22q11.21) where TrxR1 and TrxR2 are consdered as the respective cytosolic 1w1e MITOCHONDRIAL cytoplasmicand mitochondrial thioredoxin reductases, plus the thioredoxin glutathione reductases-TGR systems most likely can reduce (Trx) by fusion of the TR and an N-terminal glutaredoxin domains. As a pyridine nucleotide disulfide oxidoreductase of the oxidized GSH and GSSG (selenodiglutathione) reductase TGR structures enzyme stability, are linked to the previously characterized two thioredoxin reductases cytosolic TR1 and TR3, and one mitochondrial variant. Selenols are key metabolites at mammalian TXNRD1's active (SeCys 498) site. Thioredoxin undergoes NADPH-dependent reduction (NTRs) and reduce oxidized cysteine groups on mitochondrial TXNRD1 proteins similar to the cytosolic enzyme, from the FAD binding domain where the active cystines and the NADPH binding domain are contained, plus an interface domain (ID) of the C-terminal interface homologous to glutathione reductase identifies a mechanism of p53 mediated cell death regulation involving (TrxR) enzymes of redox homeostasis reactions to overcome the oxidative stress generating reactive oxygen species (ROS) on a complex combination of decreased apoptosis to prevent permanent cell damage and cell death that tumor cells use to evade the redox-sensitive signaling factors, or resistance to therapy. End products of lipid-peroxidation, 4-HNE-(4-Hydroxynonenal) can induce oxidative stress, other isoforms are more water-soluble adducts detoxifying such a buildup,  peroxidation might be limiting their (selenoproteins) proper expression. Thioredoxin reductase (TrxR) is the homodimeric flavoenzyme that catalyzes reduction of thioredoxin disulfide (Trx) one of the major redox control systems, involving a second interaction between NAD(P)H and/or (quinone reductase) NQO1 via the FAD-containing enzyme (TR), thioredoxin reductase forms an oxidoreductase system. TrxRs are able to reduce a number of substrate proteins other than Trx.

3qfbThe 3' UTR of selenocysteine-containing genes have a common stem-loop structure, the sec insertion sequence (selenocystine-SECIS, PDB: 2ZZ0), that is necessary for the recognition of a catalytically active Sec codon rather in the values for mitochondrial and cytosolic thioredoxins reductase (TR) domains. The Sec residue is protonated at a different pka than in comparison to that of Cysteine. Cys59-Cys64 two cysteines pair also was oxidized in the N-terminal FAD domain essential for thioredoxin-reducing activity, and the need for Sec-498 (PDB: 2J3N) to be in complex with the FAD and NADP(+) during catalysis to the N-terminal active site cysteine residues Cys59-Cys64 and from there to the C-terminal part of the other subunit which have selenotetrapeptide sequences from the other module (PDB: 2J3N). Secys498 forms, (Human PDB 3QFB,) can both be identified at active site of the enzyme Gly-499 of the subunits active Cys-497-TRXR1 (the TR1 structure PDB: 3QFB) are the mechanism(s) for the incorporation of Se into TrxRs as the amino acid selenocysteine (Sec), as well as for delivery to a variety of secondary substrates or TRX (PDB: 3QFB) in nuclei provide means to quantify glutathione (GSH) (PDB: 3H8Q) conditions of the active GRX functonally and structurally analogus to TGR (selenodiglutathione) reductase. These two were modeled parts of TGR were linked to V3 (_TXNRD1) encodes an N-terminal inter-specific glutaredoxin (PDB: 1JHB).3qfb-3h8q From the FAD binding domain-(PDB: 1ZKQ ) active cystines and the NADPH binding domain where they are contained, plus an interface domain (ID) of the C-terminal ID in complex with its substrate thioredoxin (Trx-PDB: 1TRX, TXNRD1-3QFB) bringing Cys32 in Trx1 close to Cys497 in 3H8Q to quantify glutathione (GSH) that helped in characterizing  what was separately modeled as the Thioredoxin reductase (TXNRD1) domain which are consdered as the respective cytosolic and mitochondrial thioredoxin reductases units with a model obeying standard geometry that is conceivable of human thioredoxin reductase 3's structure  glutaredoxin domain 3H8Q  in complex with the FAD and NADP(H), when replaced by the TcTR (PDB: 2W0H) trypanothione/trypanothione reductase system involves a phylum of Platyhelmintha, where a glutathione (GSH) isoform containing a fused (Grx) glutaredoxin domain  (PDB: 1JHB) is essential for the parasite survival.  The intricate substrate specificities for the thioredoxin (Trx) system which consists of native Trx and the respective cytosolic  mitochondrial thioredoxin reductase (TrxR) enzymes are likely to be of central importance to these observations as a determinant of TrxR function in general, each (the thioredoxin reductase/thioredoxin pathway) can reduce a number of different types of substrates or cross-reactive-bound enzyme fractions as active with thioredoxin.

[1.] Selenium yeast: seleno yeast PMID: 16857846
[2.] Sulforaphane From Broccoli PMID: 16377050, 12742546, 20204301, 12949356, 19595745, 17150329, 15740016, 12663510, 15998110, 17300148
[3.] Chlorella vulgaris: corresponding to a chloroplast NADPH-dependent thioredoxin reductase gene (NTR-C), in Chlorella PMID: 18029787
[4.] Scutellarin:  It can be found in Scutellaria barbata and S. lateriflora. PMID: 15131321
[5.] Curcumin (TURMERIC plant of the ginger family): PMID: 21782934, 20160040, ~15879598
[6.] Experiments in E. huxleyi genus phytoplankton PMID: 20032866
[7.] Gambogic Acid pigment of gambooge resin from tree species Garcinia gummi-gutta. PMID: 24407164
[8.] Shikonin an antioxidant (no longer approved for use,: targets the Sec residue [13.] in TrxR1 to inhibit its physiological function. see: (Methane-) methylseleninic acid (MSA)) obtained from the extracts of  plant [9.] Lithospermum erythrorhizon. PMID: 24583460
[10.] Black tea extract (BTE) theaflavin (TF) PMID: 19059456
[11.] Green tea extract-epigallocatechin-3-gallate (EGCG) PMID: 19020731
[12.] Eicosatetraenoic acid, (Mortierella Alpina Oil) Arachidonic acid (AA) all-cis-5,8,11,14-eicosatetraenoic acid, 5-Hydroxyicosatetraenoic_acid_and_5-oxo-eicosatetraenoic_acid PMID: 15123685
[13.] Juglone: In the food industry known as C.I. Natural Brown 7 and C.I. 75500. (DTNB assay, a synthetic approach for Cys and Sec residues.) PMID: 21172426, 11170645, 18382651 ... a 5,5'-[dithiobis Pyritinol: analogue, Sulbutiamine]
[14.] The antioxidant ubiquinol-10 (Q10) PMID: 12435734
[15.] Rottlerin, conductance potassium channel (BKCa++) opener, source the Kamala tree. PMID: 17581112
[16.] Ajoene a chemical compound available from garlic. PMID: 9986706
      No CiTO relationships defined

Monday, November 24, 2014

Catalase, the antioxidant heme enzyme one of three subgroups related to catalase deficiency in humans modulating the normal catalase reaction dependent on NADPH-binding catalases for function.

Catalase (CAT) is converted by decomposition and intracellular localization relationships of the main cellular antioxidant enzyme system like superoxide dismutase (SOD), peroxiredoxins (Prdx), and glutathione peroxidase (GPX) are peroxisomal matrix enzymes in the cytoplasm, translocated to the peroxisomes to catalyze hydrogen peroxide H2O2 which is decomposed to oxygen and water, locus: 11p13 (§, ). Unlike catalase, the objective of this communication, SOD which prevents the formation of Hydroxyl radicals - (HRGT) determined from constant of O2.- dismutation, and generation of reversibly inactive (CAT)-compound II, Panax ginseng could induce both transcription factors. Catalase is  composed of four identical subunits each of the subunits binds one heme-containing active site, and produces two catalase compounds HPI and HPII (PDB: 1p80) is flipped 180 degrees » with respect to the orientation of the heme related to the « root mean square to the structure of catalase, (Mutation Location) from peroxisomal catalases inactive state in compound II NADP+(H) binding pockets inverted remains similar to the structure of the wild type (Val111, PDB:1A4E, KatG) orientation on the heme proximal (PDB: 1GGK) side, inactivate catalase can be prevented by melatonin. Catalase (CAT; EC a  free radical scavenging enzyme (FRSE) is a scavenger of H2O2. Protoporphyrin - (ZnPPIX) (PDB: 1H6N), from a heme group of the 'heme-pathway, which forms catalase,' is a scavenger of antioxidant (HO-1-HMOX1) heme oxygenase, involving ROS. Catalase is part of the enzymatic defense system constituting the primary defense against ROS, zinc protoporphyrin IX (ZnPPIX) is an inhibitor of (HO-1) heme oxygenase. Catalase protects the cell from oxidative damage by the accumulation of cellular reactive oxygen species (ROS) generation systems, those peroxisomal enzymes that breaks down hydrogen peroxide after H(2)O(2) exposure, and thereby mitigates* (some contradictory* results) the toxic effects of hydrogen peroxide. In the process (The typical hydroperoxidases (CAT) known as Compound I) of the substrate of catalase, NADP+ (an inactive state, compound II) is replaced by another molecule of NADP(H) to provide protection of catalase against inactivation by (H2O2) hydrogen peroxide. Erythrocyte  [Human erythrocyte catalase (HEC), The NADPH-binding sites were empty - PDB: 1F4J, 1QQW] and plasma indices (enzymatic-antioxidants) initially implies the thiobarbituric acid-reacting substances (TBARS) based on reaction with hydroxyl radicals (OH) can release thiobarbituric acid, TBAR inhibition measures malondialdehyde (MDA - impact of coenzyme Q10) correlated (with MPO-myeloperoxidase activity -generating ROS) as co-variable, by which mulberry leaf polysaccharide (MLPII) via the decomposition of (certain) MDA, products of lipid peroxidation (LPO) were reduced. Comparisons were to specific activities of catalase (SNP) single nucleotide polymorphisms (CAT-C-262 (rs1001179) the low-risk allele) of genetic variants in both, promoter a common C/T polymorphism (262-C/T), and in nine - exonic - regions and its boundaries, occur frequently associated distally in genomic mutations, similar to those of normal catalase demonstrating changes in catalase protein level targeted to the peroxisomal matrix. The 262-C/T CAT low-risk allele is hypothetically related to the lower risk variant allele CAT Tyr308 G to A point mutation ineducable in the Japanese acatalasemia allele. The common C/T polymorphism can be targeted by dietary and/or pharmacological antioxidants, and the endogenous antioxidant defense enzymes concentration can prevent cellular lipid (LPO) peroxidative reactions occurring. Catalase is a homotetramer complex of 4 identical monofunctional subunits. Catalase is located at the peroxisome of human cells associated with several (PBDs)-peroxisomal biogenesis disorders commonly caused by mutations in the PEX genes, peroxisomal targeting signal 1 (PTS1) protein affecting in peroxisomal biogenesis, the monomeric to homotetrameric transition in the forms of peroxisome biogenesis disorder. PBDs also include Acatalasemia the only disease known to be caused by the (CAT) gene. In human catalase, the antioxidant heme enzyme, is localized in the cytoplasm to the peroxisome, nucleus, or linked with mitochondria which in most cells lack catalase (Peroxisomes do not contain DNA), its mitochondrial fraction (microperoxisome), a secondary phenomena shows physiological decline, aging and age-related reactions in mitochondrial function and disfunction. NADPH is required for the prevention of forming an inactive state of the enzyme. Antioxidative defence mechanisms, capacity and redox cycle enzyme activities increasing with Tc treatment Tinospora cordifolia (Tc), T and B cells and antibody. Both RBCs and plasma were measured on parameters of oxidative stress. Syzygium cumini aqueous leaves extract (ASc) was able to remove oxidant species in a hyperglycemic state generated in red blood cells RBC-CAT levels. Catalase alone is unable to prevent in a hyperglycemic state. Macrophages recruit other types of immune cells such as lymphocytes white blood cells (WBCs).  Catalase is dependent on the family of NADPH-binding catalases for function, the prevention and reversal of inactivation by its toxic substrate (H2O2) hydrogen peroxide. Amyloid-beta binds catalase and inhibits (H2O2) hydrogen peroxide, a reactive oxygen species, breakdown through efficient dismutation, and malonaldelhyde (MDA) determined in plasma, as well as another member of the oxidoreductase family, myeloperoxidase (MPO (EC converting H(2)O(2), the reducing equivalents produces (HOCl) hypochlorous acid a mechanism of cell-mediated antimicrobial immune defense for monofunctional catalases one of three subgroups related to catalase deficiency in humans, in micro-organisms manganese-containing catalases ('large catalases') determining in part the bifunctional activity of (KatG, PDB:1X7U) represented by bifunctional (heme) catalase-peroxidase based Bacterial-resistance mechanisms. Peroxiredoxins (Prxs, EC, bifunctional catalase-peroxidases (KatGs) two organelle systems are antioxidant enzymes of the peroxiredoxin family that oxidize and reduce H(2)O(2) hydrogen peroxide thereby modulating the catalase reaction, KatGs are not found in plants and animals. Trx (thioredoxin) a redox-regulating protein also controls the antioxidant enzyme activity of the main cellular antioxidant enzymes (AOE) superoxide dismutase (SOD) and catalase.

The function of NADPH bound to Catalase.
catalaseThe cytosine to thymidine transition of nucleotide-262 (-262C>T) Computer analysis indicated that the two variants bound promoter the Ile  (-262 C/T) and (B) Ile-262 in the 5'-flanking region carrying the T allele best captured and characterized the generation of the hydroxyl radical site in (PDB: 1DGB), (CAT) -[GLU] 330C>T transition, is known also as -262C>T. The 'T allele in comparison to the C allele' is a common C/T polymorphism frequency in the promoter region association was observed between genotypes for locus11p13 risk alleles acatalasemia mutation Asp (37C>T in exon 9) was hypothetically related to the lower risk Japanese acatalasemia allele Tyr308 a single G to A (see: rs7947841  to evaluate the link to rs769214) point mutation ineducable or near exon 9 (TC, CC, TT) of the CAT gene to which variant changes in the promoter region C/T-262 polymorphism are more closely related to CAT T/C at codon 389 in exon 9 (rs769217) polymorphism did not differ significantly from those of healthy controls in both promoter (-262 C/T) and in exonic (ASP-389 C/T) regions of the catalase (CAT). catalase Tyr 370 resolves the 25 A-long (hydrogen peroxide) channel a constriction or narrowing of the channel leading to the heme cavity ('Parameters) situated in the entrance channel to a heme protoporphyrin (ZnPPIX) (PDB: 1H6N) from a heme group, capable of heme biosynthesis' in a wide range of organisms convert it into into heme b, protoporphyrin IX-heme. Two channels lead close to the distal side.  A third channel reaching the heme proximal side Tyr 370, Ile-262 is proposed as a the 'PDB: 1DGB - variant with a substituted residue in the ASP 178 to the (Met) D181E variant PDB 1p80'.  These differences include the structure of the variant protein Val111Ala (Saccharomyces cerevisiae) related supports the existence of the 'Heme and NADP(H) binding pockets'. The omission of a 20-residue  PDB: 1F4J, (1QQW) segment corresponds to the N-terminal (blue) of catalase from human erythrocytes (HEC), or in a C-terminal (red) domain organized with an extra flavodoxin-like fold topology may provide with weak coordination the N- or C-terminal, that allows scrutiny of the origins (topology) in this report of what would otherwise remain speculative or determined with further verification.

 Biological Xenobiotic Extracts Applications of note In the presence of Catalase:

green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG)
Yamamoto T, Lewis J, Wataha J, Dickinson D, Singh B, Bollag WB, Ueta E, OsakiT, Athar M, Schuster G, Hsu S. Roles of catalase and hydrogen peroxide in greentea polyphenol-induced chemopreventive effects. J Pharmacol Exp Ther. 2004Jan;308(1):317-23. Epub 2003 Oct 20. PubMed PMID: 14569057.Furukawa A, Oikawa S, Murata M, Hiraku Y, Kawanishi S. (-)-Epigallocatechingallate causes oxidative damage to isolated and cellular DNA. Biochem Pharmacol.2003 Nov 1;66(9):1769-78. PubMed PMID: 14563487.*
Trigonella (Fenugreek)
Mohammad S, Taha A, Bamezai RN, Basir SF, Baquer NZ. Lower doses of vanadatein combination with trigonella restore altered carbohydrate metabolism andantioxidant status in alloxan-diabetic rats. Clin Chim Acta. 2004Apr;342(1-2):105-14. Erratum in: Clin Chim Acta. 2010 Aug 5;411(15-16):1158.Mohamad, Sameer [corrected to Mohammad, Sameer]. PubMed PMID: 15026271.
Aegle marmelos
Khan TH, Sultana S. Antioxidant and hepatoprotective potential of Aeglemarmelos Correa. against CCl4-induced oxidative stress and early tumor events. JEnzyme Inhib Med Chem. 2009 Apr;24(2):320-7. doi: 10.1080/14756360802167754 .PubMed PMID: 18830880.
Centella asiatica
Flora SJ, Gupta R. Beneficial effects of Centella asiatica aqueous extractagainst arsenic-induced oxidative stress and essential metal status in rats.Phytother Res. 2007 Oct;21(10):980-8. PubMed PMID: 17600859.
Mishra P, Kar A, Kale RK. Prevention of chemically induced mammarytumorigenesis by daidzein in pre-pubertal rats: the role of peroxidative damageand antioxidative enzymes. Mol Cell Biochem. 2009 May;325(1-2):149-57. doi:10.1007/s11010-009-0029-1. Epub 2009 Feb 13. PubMed PMID: 19214712.
Yadav P, Sarkar S, Bhatnagar D. Action of capparis decidua againstalloxan-induced oxidative stress and diabetes in rat tissues. Pharmacol Res. 1997Sep;36(3):221-8. PubMed PMID: 9367667.
 Kannan R, Jin M, Gamulescu MA, Hinton DR. Ceramide-induced apoptosis: role ofcatalase and hepatocyte growth factor. Free Radic Biol Med. 2004 Jul15;37(2):166-75. PubMed PMID: 15203188.
Cemek M, Caksen H, Bayiroğlu F, Cemek F, Dede S. Oxidative stress andenzymic-non-enzymic antioxidant responses in children with acute pneumonia. CellBiochem Funct. 2006 May-Jun;24(3):269-73. PubMed PMID: 16634091.
Diallyl disulfide (Allicin)
Kalayarasan S, Prabhu PN, Sriram N, Manikandan R, Arumugam M, Sudhandiran G.Diallyl sulfide enhances antioxidants and inhibits inflammation through theactivation of Nrf2 against gentamicin-induced nephrotoxicity in Wistar rats. EurJ Pharmacol. 2009 Mar 15;606(1-3):162-71. doi: 10.1016/j.ejphar.2008.12.055. Epub2009 Jan 19. PubMed PMID: 19374873.
Leucas aspera (Catechin, EGCG)
Kripa KG, Chamundeeswari D, Thanka J, Uma Maheswara Reddy C. Modulation ofinflammatory markers by the ethanolic extract of Leucas aspera in adjuvantarthritis. J Ethnopharmacol. 2011 Apr 12;134(3):1024-7. doi:10.1016/j.jep.2011.01.010. Epub 2011 Jan 18. PubMed PMID: 21251972.
Urtica dioica (nettle suppliment)Ozen T, Korkmaz H. Modulatory effect of Urtica dioica L. (Urticaceae) leaf
extract on biotransformation enzyme systems, antioxidant enzymes, lactatedehydrogenase and lipid peroxidation in mice. Phytomedicine. 2003;10(5):405-15.PubMed PMID: 12834006.
Justicia adhatoda
Singh RP, Padmavathi B, Rao AR. Modulatory influence of Adhatoda vesica(Justicia adhatoda) leaf extract on the enzymes of xenobiotic metabolism,antioxidant status and lipid peroxidation in mice. Mol Cell Biochem. 2000Oct;213(1-2):99-109. PubMed PMID: 11129964.
Phyllanthus niruri L. (Euphorbiaceae) (P. niruri)
Bhattacharjee R, Sil PC. Protein isolate from the herb, Phyllanthus niruri L.(Euphorbiaceae), plays hepatoprotective role against carbon tetrachloride inducedliver damage via its antioxidant properties. Food Chem Toxicol. 2007May;45(5):817-26. Epub 2006 Nov 11. PubMed PMID: 17175085.
Tinospora cordifolia
Sharma V, Pandey D. Protective Role of Tinospora cordifolia againstLead-induced Hepatotoxicity. Toxicol Int. 2010 Jan;17(1):12-7. doi:10.4103/0971-6580.68343. PubMed PMID: 21042467; PubMed Central PMCID: PMC2964743.
Aher V, Kumar Wahi A. Biotechnological Approach to Evaluate theImmunomodulatory Activity of Ethanolic Extract of Tinospora cordifolia Stem(Mango Plant Climber). Iran J Pharm Res. 2012 Summer;11(3):863-72. PubMed PMID:24250513; PubMed Central PMCID: PMC3813135.
coenzyme Q10
Lee BJ, Lin YC, Huang YC, Ko YW, Hsia S, Lin PT. The relationship betweencoenzyme Q10, oxidative stress, and antioxidant enzymes activities and coronaryartery disease. ScientificWorldJournal. 2012;2012:792756. doi:10.1100/2012/792756. Epub 2012 May 3. PubMed PMID: 22645453; PubMed CentralPMCID: PMC3356738.
Dietary carotenoid-rich pequi oil
Miranda-Vilela AL, Akimoto AK, Alves PC, Pereira LC, Gonçalves CA,Klautau-Guimarães MN, Grisolia CK. Dietary carotenoid-rich pequi oil reducesplasma lipid peroxidation and DNA damage in runners and evidence for anassociation with MnSOD genetic variant -Val9Ala. Genet Mol Res. 2009 Dec15;8(4):1481-95. doi: 10.4238/vol8-4gmr684. PubMed PMID: 20082261.
Tinospora cordifolia  (Mango Plant Climber) extract from Tinospora known as Tinofend Aher V, Kumar Wahi A. Biotechnological Approach to Evaluate theImmunomodulatory Activity of Ethanolic Extract of Tinospora cordifolia Stem(Mango Plant Climber). Iran J Pharm Res. 2012 Summer;11(3):863-72. PubMed PMID:24250513; PubMed Central PMCID: PMC3813135.
 mulberry leaf polysaccharide (MLPII)
Ren C, Zhang Y, Cui W, Lu G, Wang Y, Gao H, Huang L, Mu Z. A polysaccharideextract of mulberry leaf ameliorates hepatic glucose metabolism and insulinsignaling in rats with type 2 diabetes induced by high fat-diet andstreptozotocin. Int J Biol Macromol. 2014 Oct 11. pii: S0141-8130(14)00674-6.doi: 10.1016/j.ijbiomac.2014.09.060. [Epub ahead of print] PubMed PMID: 25316427.
five widely studied medicinal plants (Protandim)
Nelson SK, Bose SK, Grunwald GK, Myhill P, McCord JM. The induction of humansuperoxide dismutase and catalase in vivo: a fundamentally new approach toantioxidant therapy. Free Radic Biol Med. 2006 Jan 15;40(2):341-7. PubMed PMID:16413416.
Mayo JC, Tan DX, Sainz RM, Lopez-Burillo S, Reiter RJ. Oxidative damage tocatalase induced by peroxyl radicals: functional protection by melatonin andother antioxidants. Free Radic Res. 2003 May;37(5):543-53. PubMed PMID: 12797476.
Protective effect of harmaline
Kim DH, Jang YY, Han ES, Lee CS. Protective effect of harmaline and harmalolagainst dopamine- and 6-hydroxydopamine-induced oxidative damage of brainmitochondria and synaptosomes, and viability loss of PC12 cells. Eur J Neurosci.2001 May;13(10):1861-72. PubMed PMID: 11403679.
horseradish peroxidase (HRP)
Shen L, Hu N. Heme protein films with polyamidoamine dendrimer: directelectrochemistry and electrocatalysis. Biochim Biophys Acta. 2004 Jan30;1608(1):23-33. PubMed PMID: 14741582.
Selegiline (--)Deprenyl
Kitani K, Minami C, Isobe K, Maehara K, Kanai S, Ivy GO, Carrillo MC. Why(--)deprenyl prolongs survivals of experimental animals: increase of anti-oxidantenzymes in brain and other body tissues as well as mobilization of varioushumoral factors may lead to systemic anti-aging effects. Mech Ageing Dev. 2002Apr 30;123(8):1087-100. Review. PubMed PMID: 12044958.
Rhodiola rosea
Bayliak MM, Lushchak VI. The golden root, Rhodiola rosea, prolongs lifespanbut decreases oxidative stress resistance in yeast Saccharomyces cerevisiae.Phytomedicine. 2011 Nov 15;18(14):1262-8. doi: 10.1016/j.phymed.2011.06.010. Epub2011 Jul 30. PubMed PMID: 21802922.
Kiziltunc A, Coğalgil S, Cerrahoğlu L. Carnitine and antioxidants levels inpatients with rheumatoid arthritis. Scand J Rheumatol. 1998;27(6):441-5. PubMedPMID: 9855215.
 Syzygium cumini
 De Bona KS, Bellé LP, Sari MH, Thomé G, Schetinger MR, Morsch VM, Boligon A,
Athayde ML, Pigatto AS, Moretto MB. Syzygium cumini extract decrease adenosine
deaminase, 5'nucleotidase activities and oxidative damage in platelets of
diabetic patients. Cell Physiol Biochem. 2010;26(4-5):729-38. doi:
10.1159/000322340. Epub 2010 Oct 29. PubMed PMID: 21063110.

Wednesday, July 16, 2014

Characterization of human thioredoxin system and the potential cellular responses encoded to observe the Thioredoxin-Trx1 reversibly regulated redox sites.

Thioredoxin: human TXN, is a oxidoreductase enzyme in the status of a 12 kDa cellular redox-reductase reaction (70-kDa in bacteria, fungi and plants), a cellular defense mechanisms against oxidative stress of the cell, and numerous cytosolic processes in all cells. Txn1 is a pleiotropic cellular causative gene factor which has numerous functions. Chromosome 3p12-p11 shares homology with human thioredoxin gene Trx1, Trx80: 9q31.3; (§, ). Here the following reaction is the possible mechanisms of the thioredoxin-catalyzed reduction and re-oxidation of its characteristic cystine residues.
 The TXN gene, consists of the first of 5 exons separated by 4 introns and is located 22 bp downstream from the only known basal TATA box factor TBP-2/TXNIP vitamin D(3) up-regulated protein 1-VDUP1, negatively regulating TRX function, and exhibiting cellular growth and suppressive (cancer) activity.
 TRX inhibited Apoptosis signal-regulating kinase-ASK1 kinase (MAP3K5), activity, dependent on two cysteine residues in the N-terminal domain of ASK1 on the redox (regulation) forming intramolecular disulfide between the status of TXN. Two cysteine residues (N-terminal C32S or Trx C-terminal C35S and/or a Trx-CS double mutation) remaining trapped with the Ask1 as a inactive high-molecular-mass complex, blocking its reduction to release Trx from ASK1 depends on intramolecular disulfide to catalyze the reduction of the redox regulation of TRX. Trx and a thiol-specific antioxidant thioredoxin peroxidase-2 orthologue (Tpx) in various* biological phenomena is involved in redox regulation (NADPH-the thioredoxin system) of the dithiol-disulfide active site.
 An apoptosis signal transduction pathway through stimulus-coupled S-nitrosation of cysteine, has two critical (almost identical) cysteine residues in the Trx redox-active center. Where a disulfide exchange reaction between oxidized Txnip [thioredoxin-interacting protein; mouse Vdup1] and reduced TXN occurs. Txnip (-when used to investigate cardiac hypertrophy) is a regulator of biomechanical signaling. Hydrogen peroxide downregulated expression is the only known function associated with an incomplete TRX response through stimulus-coupled S-nitrosation of cysteine residues. Peroxiredoxin PrxIII-'Tpx1 serves as' a tandem (dimer) thioredoxin (Trx2) and NADP-linked thioredoxin reductase (TRR2-TxnR1), are Trx mechanisms of the two electron donor system.
 Cytosolic caspase-3 was maintained by S-nitrosation, consistent with cytosolic and mitochondria, Trx-1 contain equivalent Trx systems, which enabled identification of caspase-3 substrates where TXN may regulate S-nitrosation with the redox center of TXN specific (C73S) to Nitric oxide-NO cellular signal transduction associated with  inhibition of apoptosis or mutant Trx neurotoxicity. EGCG° (epigallocatechin-3-gallate) may be useful in cell survival on caspase-(3_dependent)-neuronal apoptosis where a membrane reaction, a reduced hormesis consequently triggers the apoptosis effect and direct or indirectly numerous protein-protein interactions and basal cofactor substrates which occur between caspase-3 and Trx. The effect of  exercise training via activation of caspase-3 has a decrease in superoxide, and increase of Trx-1 levels in brain. Protection from mechanical stress identified, NSF- N-ethylmaleimide transduced into a TRX peroxidase response via mechanical force of a typical transnitrosylated  Casp3, attenuated  Trx1 2-cysteines which directly transnitrosylates Peroxiredoxins. C32S ( redox potential) was identified as thiol-reducing system, which lacks reducing activitiy (non-active C69S and Cys(73) both monomeric) or a reversible regulating function in the presence of caspase 3 activity is a process found in the presence of NADP and TrxR.
 There are at least two thioredoxin reductive or oxidative** (reductases / peroxiredoxin) regulated systems. The mutant 32CXXC35' motif of thioredoxin nitrosation sites, where two cysteines are separated by two other amino acids, and codes for an additional three cysteines where the Cys 62/C73S (not monomers) sidechain the active site of Cys 62 also can form several disulphides and be modified by the carbon-bonded sulfhydryl, where the  thiol reducing system, was evident.
 Intracellular TRX/ADF (Adult T cell leukemia-derived factor HTLV-I) can regulate cell nuclei, protein-nucleic acid interactions. Transnitrosylation and denitrosylation is a reversible Post-translational (PTM) altered by redox modification of different cysteine residues (C32-73S) in Trx1, S-nitrosation or its interactions with other proteins and DNA-dependent nuclear processes. NFKappaB - REF-1 redox factor 1  involving Cys62, in the two complexes, are correlated as N ⇔ C-terminal responses with  TRX-1 nuclear migration through the reduction of a pleiotropic cellular factor. TRX redox activities of protein-protein cysteine residues is identical to a DNA repair enzyme through various cytoplasmic aspects mediating cellular responses in the 'nucleus'. The DNA binding activity and transactivation of 'AP-1' activator proteins (JUN-proto* oncogen) depends on the reduction between the sulfhydryl of cysteines to keep Trx1 reduced, is demonstrated in cells. Selenium-dependent seleneocysteine based peroxidase reductants, reduce Lipoic acid stereoselectively under the same TRX rather than GSH-PX1-glutathione peroxidase oxidative stress conditions. Sense-antisense (TRX) antiapoptoitic interactions nitrosylated at Cys73 are attenuated and integrated into the host cell under oxidative conditions, in which thioredoxin (TRX), and a cellular TRX reducing catalyst agent (DTT-redox reagent) to S-nitrosoglutathione (GSNO) intermediate via cysteine residues 'influences'-catalyst mediated (post-translational modifications) PTMs; and possibly 1,25D(3)-Calcitriol; NADPH:oxygen oxidoreductases correlated with  (Trx-1) a protein disulfide oxidoreductase.
 Peroxynitrite** converts superoxide to hydrogen peroxide (H2O2)-induced Trx degradation, in concentrations that detoxify reactive oxygen species (ROS), demonstrated by superoxide dismutases (SOD)-catalase: and peroxidases, converting superoxide to hydrogen peroxide which is decomposed to water plus oxidized thioredoxin to maintain the anti-apoptotic (C62) function of thioredoxins additional five sulfhydryl group thiols in the fully reduced state, in a Trx-dependent manner. Reactive oxygen species (ROS) can cause DNA damage, and uncontrolled cellular proliferation or apoptotic death of cancer cells.The NADPH (Trx system) oxidizing substrate-dependent reduction of Thioredoxin reductase-TrxR has a reversibly modulated role in restoration of GR (glucocorticoid receptor) function, and DNA binding domain.

(Click on image to Zoom)
  1XOB Secreted Trx may participate in removing inhibitors of collagen-degrading metalloproteinases. PMID: 14503974 the molecular mechanisms underlying functional the TR1-Trx1 redox pair and structure determination of an active site of the ligand mini-stromelysin-1 TR-1 augmentation composed of TR (Trx reductase activities) the main function of TR1 here is to reduce Trx1 also validated as a ligand PMID; 23105116, have been characterized between ligand bound and free structures PMID; 20661909, for specific isolation of  C35S selenocysteine (SeCys)-containing protein shows the best docking position found, consists of one strand at position [PROline]76:A.side chain: from the four-stranded antiparallel beta sheet was with wild-type TrxA C32-35S located in the Thioredoxin_fold (PDB accession code 1XOB: PMID: 15987909) , TR1 as a single hybrid PDB (Cys32 and Cys35 for Trx1, and for TR1) pubmed/20536427 investigate the possible mechanism. {{{During this reduction, the thiol-disulfide oxidoreductase thioredoxin-1 (Trx1) linkedNADP thioredoxin reductase (TRR2) a working model suggesting that deregulation of the thioredoxin reductase TXNRD1 and|}}} its characteristic substrate thioredoxin (TR [1]), concomitant with diminution of their Trx reductase cellular contents is highly related to glutamate excitotoxicity PMID: 20620191; TR1: hStromelysin-1

 enlargeAn ET (electron transfer) mechanism from NADPH and another enzyme thioredoxin reductase pubmed/17369362 the charged residue aspartate D60 (Fig.2) pubmed/9369469/ plays a role in the degradation of proteins and in apoptotic processes induced by oxidative stress PMID: 16263712  to determine the effect of  zerumbone ZSD1 (from shampoo ginger; Name: Alpha-humulene) on NADP-malate dehydrogenase,NADP TRX dependent oxidoreductase, that NADPH does not contain. Monomeric Thioredoxin is present across phyla from humans to plants PMID: 20661909, 11012661 mediated in vivo by thioredoxin-catalyzed reduction and re-oxidation of cystine residues PubMed id: 10196131 (Fig.3-PDB
: 1CIV, NADP). Trx is able to activate vegetal NADP-malate dehydrogenase PMID: 3170595 (excluding the initial methionine) Met is located at the N-terminal - PMID: 11807942, 2684271. A relatively rigid local configuration for the TRX-aspartate residue D60 is found but which implies that the (NADP-TrxR) protein fluctuates among the numerous protein models and mutations over the time scales fluctuations.

  • Trx (thioredoxin) a redox-regulating protein also controls the antioxidant enzyme activity of the main cellular antioxidant enzymes (AOE) superoxide dismutase (SOD) and catalase.[]

  • (Reference: 1-189)

    Sunday, April 13, 2014

    Gluathione peroxidase (GSH-Px1-GPX1) a extracellular selenoenzyme expression modulates xenobiotic metabolising enzymes.

         Glutathione peroxidase (EC protects against oxidative damage via the chemoprotective action of nitric-oxide mediated lipid peroxidation and anti oxidative defense by gluathione (GSH-Px1-GPX1) a extracellular selenoenzyme, extracellular glutathione peroxidase (E-GPx) and cellular (C-GPx) detoxifies hydroperoxides. Other antioxidant genes (AOX) as Gpx1, is located in the cytosol and in (mt) mitochondria. Epithelial antioxidative enzymes (AOEs) are activities of GSH-Px1 (gluathione peroxidase), (SOD) superoxide dismutase, and thioredoxine reductase (TXNRD1) by itself or with thioredoxin (Trx) are antioxidant enzymes. Glutaredoxin (Grx) are reduced by the oxidation of glutathione an antioxidant, (The effect of iridoid  glucosides such as oleuropein an antioxidant, can often be bound to glucose.) phenolic compound isothiocyanate sulforaphane found in olive leaf, increased cell-lysate NAD(P)H:quinone oxidoreductase (NQO1) phase II activities reduction reactions, catalyzed such as by glutathione-S-transferase (GST) can catalyze the conjugation back to the thiol group and other GPx mimics (converted into selenocysteine), to the reaction site of glutathione (GSH) and antioxidants, implying (GR) reduction reactions back to glutathione, are an evolutionary relationship between GST and GPx/glutathione system defense in oxidative stress. "Glutathione" peroxidase (Gpx) content, and glutathione reductase (GR) components compose the glutathione (GSH) system, this contains Selenocysteine (Sec), the 21st amino acid at the active GPX site (Homo sapiens chromosome 3, GRCh37 primary reference: rs644261)- TGA  => UGA (selenocysteine, which occurs at the active site of  glutathione peroxidase GPX1 is coded by UGA, isoform 1 NM_201397.1-variant 1 represents the shorter transcript that  encodes the longer isoform 1, as compared to isoform 2- NM_000581.2 variant 2); (rs1050450) is intronless and has a shorter C-terminus. They represent the cDNA as a molecular mechanism (TGA) for down-regulation of mRNA expression and transcriptional code is a regulatory switch at the translational-step delivered to the ribosome in genes similar to Glutathione peroxidase 1 (GP, Gpx1, GSHPX1): locus 3p13-q12 (§, ,). GSH-Px is an essential nutrient selenium dependent GPX, by which mRNA translational repression of selenium-binding protein (SBP1) is accomplished when GPX1 increased in human plasma, if selenium-deficient, while independent of Se values in leukocyte (White blood cells) from correspondingly damaged DNA. In fibroblast activity, GPx1 was effective through the prevention or repair of DNA damage. The reductive detoxification of peroxides in cells modulates xenobiotic metabolising enzymes via anticarcinogen supplementation, e.g. selenium-yeast  in human plasma. GPX in turn, can lead to carcinogenesis. The heterozygote has an intraerythrocytic environment (red blood cell) with the favorable higher peroxidase activities role in malarial resistance. An in-frame GCG trinucleotide repeat was homozygous for the pseudogene GPX1 Pro197Leu-like two alleles associated with 6 GCG repeats coding for a polyalanine tract. CuZn-SOD (copper/zinc-superoxide dismutase) and other oxidoreductases contribute to the cellular defenses, repair of oxidative damage to DNA. Chronic hyperglycemia (excessive blood sugar) causes oxidative stress, 'Extract silymarin and Berberine-'may' overcome insulin resistance. And for diabetes Astragalus membranaceus  can improve the protective effect, an extract from Shidagonglao roots (Mahonia fortunei)  or the effects of Berberine from the main alkaloid of Coptis chinensis  are agents for preventing sepsis and its lipopolysaccharide (LPS) complications in human microvascular endothelial cells. GPX is down-regulated and peroxiredoxin (PRX) is up-regulated. Both use thioredoxin (Gpx and Prx, suppress Trx, a cysteine-based thioredoxin-specific GPx-Txn expression.) to recharge after reducing hydrogen peroxide (H2O2) along with other cellular molecules. Also found in transcripts in ocular tissues from oxidative anterior damaged cells,  GSH-dependent recombinant human lens thioltransferase (RHLT)* being  its repair systems. GPX1 could supress staurosporine-induced late generation of ROS, corresponding to reduction in visual loss.  Its role in pathogenesis of  (inflammatory disorders of blood antioxidant enzyme system) as an autoimmune disease background, appears to be the hydroperoxide metabolism in diverse pathogens*, an enzyme by single administration streptozotocin  (60 mg/kg) of negative implication, oxidative damage or antioxidant status when examined in contrast as metabolic syndrome through the GPX down-regulation are comparable, with reduced-enzyme-activity to the T allele of the GPx-1 genetic leucine/proline polymorphism at codon 198  approximately 70% for pro197 and 30% for leu197 named Pro198Leu (rs1050450). The leucine-containing allele was less responsive to GPx-1 enzyme activity. Thioltransferase (TTase) with GPx the dethiolating enzyme, thiol* catalysis glutaredoxin thioltransferase (Grx) content and activity to the thiol status produced by the oxidation of glutathione: a seleno-organic compound ebselen  (2-phenyl-1,2-benzisoselenazol-3(2H)-one) catalyzed in vitro, has been reported to '« mimic » development of small-molecule selenium compounds' ('synthetic antioxidant' GPX)  required for, a diphenyl diselenide PhSe group 'in the catalytic activities' is introduced by reaction (a monocyte-derived soluble protein (M-DSP/Gpx1) with 5-LO, (5-lipoxygenase ) activity this 'recovered (M-DSP)-GPx inactivation'. In which Serum Malondialdehyde (MDA) a marker (oxidative activity) generated from, reactive oxygen species (ROS) is thought to cause DNA damage with various antioxidants usually homeostatically controlled by endogenous superoxide dismutase (SOD), as a by-product and the oxygen-sensor neuroglobin (Nb), GSHPx reactive neurons or in brief neuronal damage (apoptosis) after ischemia. Antioxidant enzymes such as Cu/Zn-superoxide dismutase (SOD) and a 21-kD protein (involved in neuroprotection) GPx1 both in the free radical chain, protects neurons and Microglial cells. Microglial cells are, sensitive to small changes from Reactive oxygen species (ROS), free radical scavenging enzymes-mediated apoptosis. Neuronal loss and deteriorating CNS function: is linked to the pentose phosphate shunt, the (PPP) pentose phosphate pathway, has a relatively low content of enzymatic antioxidants, in a higher cellular ROS level to oxidative stress. A candidate (SePP1) selenoprotein (P-plasma) or  genetic variations homologous to GPX1 are rapidly degraded at relative low selenium concentrations. Microsomal (reconstituted fraction) glutathione transferase-1 (hGSTP1) decreased cytotoxicity ( cartilage degradation and regeneration [Leucas aspera] to mitochondria damage, directed to citrulline- containing proteins) by effects of hydrogen peroxide 'H(2)O(2), which causes lipid peroxidation (LPO) in the (ER) endoplasmic reticulum. In which LPO product Malondialdehyde and other Thiobarbituric acid reactive substances - TBARS - are formed as a byproduct, when the effects of GPX1 ( glutathione peroxidase 1)' is measured, the effects of Centella asiatica  extract detoxifies. Antioxidants and detoxication agents as antigenotoxic* agents (isoflavones via dietary intake) were also observed as cytogenetic end-points* of carcinogenesis. Over-expression could drain the  reduced glutathione ( hepatic and GSH dependent enzymes), cellular glutathione (GSH) levels, GSH acts as a feedback rate-limiting inhibitor of its synthesizing enzyme GCL (gamma-glutamyl-cysteine synthetase) activity,  Diosgenin  is a useful Marker degradation-compound of Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) against oxidation. The compound buthionine sulfoximine (BSO) inhibits the first step of glutathione synthesis, concerning the mechanism of GSH depletion. Gpx suppresses (thioredoxin) Trx - expression, which augments Anti-clastogenic (mutagenic agents), potential DNA-binding (heritable multigenerational/evolutionary tolerance), in a cDNA open reading frame (ORF) GPx1 is a small inversion (~pericentric), incorporating the co-translational selenocysteine which may be unique to the insertion sequence elements.

    (Click on image to zoom)
          gpx1Biological Assembly GPx-1 tetrameric structure with an altered carcinogen metabolism and reduce oxygen tension to explain the anti-carcinogenic effects, the redox donor (hTXN-oxidoreductase Figure 4) status  (Figure 2) of one oxygen atom limited to only two regions may carry missense variant (rasmol_php_C and _D) a reaction incorporated into the overall tetrameric structures instability potentially in humans through modulation of biosynthetic and genetically modified GSH enzymes binding the selenocysteine insertion sequence elements. The specific activity of the enzyme Sec suggest how the molecular pathway might work, as the glutathione pathway may influence the enzyme Sec reaction site incorporation sequence in the 3'-untranslated region UTR of glutathione (GSH) may further reveal a signaling pathway that is activated. The differing and interacting roles of GPX1 and (Sec.) Selenocysteine Synthase [doi: 10.2210/rcsb_pdb/mom_2008_8] both vectorsgpx1together with glutathione (HUMAN GLUTATHIONE TRANSFERASE (HGST) PDB ID: 1LJR ligand component GSH: C10 H17 N3 O6 S, molecules colored: aquamarine) did; activates two multiple signaling pathways in one of the Gpx1 variants 1 or 2 nucleotide, the nonsense codon, UGA has both, related to the antioxidative pathway vectors together PDB ID: 1gp1 (2-AMINO-3-SELENINO-PROPIONIC ACID: ALANINE  molecule colored: purple), is located near the selenocysteine insertion sequence element PDB ID: 2F8A (rainbow colored: ribbons) mutant of  GPX1. Interrogation of data based on experimentally determined models are limited but revealed network structures that dynamically conveyed information from the antioxidant enzymes that share a common pathway considered most important in the selenocysteine synthesis pathway from the information suggested, and they implicate at least one selenoprotein (GPx-1) in the process.