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David J Grdina - One of the best experts on this subject based on the ideXlab platform.
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a Manganese Superoxide Dismutase sod2 mediated adaptive response
Radiation Research, 2013Co-Authors: David J Grdina, Jeffrey S Murley, Richard C Miller, Helena J Mauceri, Harold G Sutton, Michael J Thirman, Gayle E Woloschak, Ralph R WeichselbaumAbstract:Very low doses of ionizing radiation, 5 to 100 mGy, can induce adaptive responses characterized by elevation in cell survival and reduction in micronuclei formation. Utilizing these end points, RKO human colon carcinoma and transformed mouse embryo fibroblasts (MEF), wild-type or knockout cells missing TNF receptors 1 and 2 (TNFR1–R2–), and C57BL/6 and TNFR1–R2– knockout mice, we demonstrate that intact TNF signaling is required for induction of elevated Manganese Superoxide Dismutase (SOD2) activity (P < 0.001) and the subsequent expression of these SOD2-mediated adaptive responses when cells are challenged at a later time with 2 Gy. In contrast, amifostine's free thiol form WR1065 can directly activate NF-κB giving rise to elevated SOD2 activity 24 h later and induce an adaptive response in both MEF wild-type and TNF signaling defective TNFR1–R2– cells. Transfection of cells with SOD2 siRNA completely abolishes both the elevation in SOD2 activity and expression of the adaptive responses. These results w...
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maintenance of Manganese Superoxide Dismutase sod2 mediated delayed radioprotection induced by repeated administration of the free thiol form of amifostine
Radiation Research, 2008Co-Authors: Jeffrey S Murley, Danupon Nantajit, Kenneth L Baker, Yasushi Kataoka, David J GrdinaAbstract:Abstract Murley, J. S., Nantajit, D., Baker, K. L., Kataoka, Y., Li, J. J. and Grdina, D. J. Maintenance of Manganese Superoxide Dismutase (SOD2)-Mediated Delayed Radioprotection Induced by Repeated Administration of the Free Thiol Form of Amifostine. Radiat. Res. 169, 495–505 (2008). Thiol-containing drugs such as WR1065, the free thiol form of amifostine, have been shown to induce a delayed radioprotective effect in both malignant and non-malignant cells. In mammalian cells exposed to a dose as low as 40 μM WR1065, the redox-sensitive nuclear transcription factor κB (NFκB) is activated, leading to an elevation in the expression of the antioxidant gene Manganese Superoxide Dismutase (SOD2) and a concomitant increase in active SOD2 enzyme levels that peaks 24 to 32 h later. Exposure of cells to ionizing radiation during the period of elevated SOD2 enzymatic activity results in an enhanced radiation resistance. This is seen as an increase in surviving fraction as determined by standard colony formation ass...
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Manganese Superoxide Dismutase sod2 mediated delayed radioprotection induced by the free thiol form of amifostine and tumor necrosis factor α
Radiation Research, 2007Co-Authors: Jeffrey S Murley, Alan M. Diamond, Kenneth L Baker, Yasushi Kataoka, William F Morgan, David J GrdinaAbstract:Abstract Murley, J. S., Kataoka, Y., Baker, K. L., Diamond, A. M., Morgan, W. F. and Grdina, D. J. Manganese Superoxide Dismutase (SOD2)-Mediated Delayed Radioprotection Induced by the Free Thiol Form of Amifostine and Tumor Necrosis Factor α. Radiat. Res. 167, 465–474 (2007). RKO36 cells, a subclone of RKO colorectal carcinoma cells that have been stably transfected with the pCMV-EGFP2Xho vector, were grown to confluence and then exposed to either the radioprotector WR-1065, i.e. the active thiol form of amifostine, for 30 min at doses of 40 μM and 4 mM or the cytokine tumor necrosis factor α (TNFα, TNFA) for 30 min at a concentration of 10 ng/ml and then washed. Total protein was isolated as a function of time up to 32 h after these treatments. Both doses of WR-1065 as well as the concentration of TNFα used were effective in elevating intracellular levels of the antioxidant protein SOD2 (also known as MnSOD) at least 15-fold over background levels as determined by Western blot analysis, while measured S...
Jeffrey S Murley - One of the best experts on this subject based on the ideXlab platform.
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a Manganese Superoxide Dismutase sod2 mediated adaptive response
Radiation Research, 2013Co-Authors: David J Grdina, Jeffrey S Murley, Richard C Miller, Helena J Mauceri, Harold G Sutton, Michael J Thirman, Gayle E Woloschak, Ralph R WeichselbaumAbstract:Very low doses of ionizing radiation, 5 to 100 mGy, can induce adaptive responses characterized by elevation in cell survival and reduction in micronuclei formation. Utilizing these end points, RKO human colon carcinoma and transformed mouse embryo fibroblasts (MEF), wild-type or knockout cells missing TNF receptors 1 and 2 (TNFR1–R2–), and C57BL/6 and TNFR1–R2– knockout mice, we demonstrate that intact TNF signaling is required for induction of elevated Manganese Superoxide Dismutase (SOD2) activity (P < 0.001) and the subsequent expression of these SOD2-mediated adaptive responses when cells are challenged at a later time with 2 Gy. In contrast, amifostine's free thiol form WR1065 can directly activate NF-κB giving rise to elevated SOD2 activity 24 h later and induce an adaptive response in both MEF wild-type and TNF signaling defective TNFR1–R2– cells. Transfection of cells with SOD2 siRNA completely abolishes both the elevation in SOD2 activity and expression of the adaptive responses. These results w...
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maintenance of Manganese Superoxide Dismutase sod2 mediated delayed radioprotection induced by repeated administration of the free thiol form of amifostine
Radiation Research, 2008Co-Authors: Jeffrey S Murley, Danupon Nantajit, Kenneth L Baker, Yasushi Kataoka, David J GrdinaAbstract:Abstract Murley, J. S., Nantajit, D., Baker, K. L., Kataoka, Y., Li, J. J. and Grdina, D. J. Maintenance of Manganese Superoxide Dismutase (SOD2)-Mediated Delayed Radioprotection Induced by Repeated Administration of the Free Thiol Form of Amifostine. Radiat. Res. 169, 495–505 (2008). Thiol-containing drugs such as WR1065, the free thiol form of amifostine, have been shown to induce a delayed radioprotective effect in both malignant and non-malignant cells. In mammalian cells exposed to a dose as low as 40 μM WR1065, the redox-sensitive nuclear transcription factor κB (NFκB) is activated, leading to an elevation in the expression of the antioxidant gene Manganese Superoxide Dismutase (SOD2) and a concomitant increase in active SOD2 enzyme levels that peaks 24 to 32 h later. Exposure of cells to ionizing radiation during the period of elevated SOD2 enzymatic activity results in an enhanced radiation resistance. This is seen as an increase in surviving fraction as determined by standard colony formation ass...
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Manganese Superoxide Dismutase sod2 mediated delayed radioprotection induced by the free thiol form of amifostine and tumor necrosis factor α
Radiation Research, 2007Co-Authors: Jeffrey S Murley, Alan M. Diamond, Kenneth L Baker, Yasushi Kataoka, William F Morgan, David J GrdinaAbstract:Abstract Murley, J. S., Kataoka, Y., Baker, K. L., Diamond, A. M., Morgan, W. F. and Grdina, D. J. Manganese Superoxide Dismutase (SOD2)-Mediated Delayed Radioprotection Induced by the Free Thiol Form of Amifostine and Tumor Necrosis Factor α. Radiat. Res. 167, 465–474 (2007). RKO36 cells, a subclone of RKO colorectal carcinoma cells that have been stably transfected with the pCMV-EGFP2Xho vector, were grown to confluence and then exposed to either the radioprotector WR-1065, i.e. the active thiol form of amifostine, for 30 min at doses of 40 μM and 4 mM or the cytokine tumor necrosis factor α (TNFα, TNFA) for 30 min at a concentration of 10 ng/ml and then washed. Total protein was isolated as a function of time up to 32 h after these treatments. Both doses of WR-1065 as well as the concentration of TNFα used were effective in elevating intracellular levels of the antioxidant protein SOD2 (also known as MnSOD) at least 15-fold over background levels as determined by Western blot analysis, while measured S...
Joel S Greenberger - One of the best experts on this subject based on the ideXlab platform.
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Gene Therapy for Systemic or Organ Specific Delivery of Manganese Superoxide Dismutase
'MDPI AG', 2021Co-Authors: Joel S Greenberger, Amitava Mukherjee, Michael W EpperlyAbstract:Manganese Superoxide Dismutase (MnSOD) is a dominant component of the antioxidant defense system in mammalian cells. Since ionizing irradiation induces profound oxidative stress, it was logical to test the effect of overexpression of MnSOD on radioresistance. This task was accomplished by introduction of a transgene for MnSOD into cells in vitro and into organs in vivo, and both paradigms showed clear radioresistance following overexpression. During the course of development and clinical application of using MnSOD as a radioprotector, several prominent observations were made by Larry Oberley, Joel Greenberger, and Michael Epperly which include (1) mitochondrial localization of either Manganese Superoxide Dismutase or copper/zinc SOD was required to provide optimal radiation protection; (2) the time required for optimal expression was 12–18 h, and while acceptable for radiation protection, the time delay was impractical for radiation mitigation; (3) significant increases in intracellular elevation of MnSOD activity were required for effective radioprotection. Lessons learned during the development of MnSOD gene therapy have provided a strategy for delivery of small molecule SOD mimics, which are faster acting and have shown the potential for both radiation protection and mitigation. The purpose of this review is to summarize the current status of using MnSOD-PL and SOD mimetics as radioprotectors and radiomitigators
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radioprotection in vitro and in vivo by minicircle plasmid carrying the human Manganese Superoxide Dismutase transgene
Human Gene Therapy, 2008Co-Authors: Xichen Zhang, Darcy Franicola, Michael W Epperly, Mark A Kay, Zhiying Chen, Tracy Dixon, Benjamin A Greenberger, Paavani Komanduri, Joel S GreenbergerAbstract:Abstract Manganese Superoxide Dismutase plasmid liposomes (MnSOD-PL) confer organ-specific in vivo ionizing irradiation protection. To prepare for potential intravenous clinical trials of systemic MnSOD-PL for radioprotection in humans, plasmid and bacterial sequences were removed and a new minicircle construct was tested. Minicircle MnSOD was purified and then cotransfected into 32D cl 3 murine interleukin-3-dependent hematopoietic progenitor cells along with another plasmid carrying the neo gene. Cells were selected in G418 (50 μg/ml) and cloned by limiting dilution. Biochemical analysis of minicircle MnSOD-transfected cells showed an MnSOD biochemical activity level of 5.8 ± 0.5 U/mg compared with 2.7 ± 0.1 U/mg for control 32D cl 3 cells (p = 0.0039). 32D-mc-MnSOD cells were as radioresistant as full-length MnSOD-PL transgene-expressing 2C6 cells, relative to 32D cl 3 parent cells, with an increased shoulder on the radiation survival curve (\documentclass{aastex}\usepackage{amsbsy}\usepackage{amsfonts...
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prevention of radiation induced oral cavity mucositis by plasmid liposome delivery of the human Manganese Superoxide Dismutase sod2 transgene
Radiation Research, 2003Co-Authors: Hongliang Guo, Jose A Seixassilva, Michael W Epperly, Joan Gretton, Dong M Shin, Dafna Barsagi, Herbert Archer, Joel S GreenbergerAbstract:Abstract Guo, H., Seixas-Silva, Jr., J. A., Epperly, M. W., Gretton, J. E., Shin, D. M., Bar-Sagi, D., Archer, H. and Greenberger, J. S. Prevention of Radiation-Induced Oral Cavity Mucositis by Plasmid/Liposome Delivery of the Human Manganese Superoxide Dismutase (SOD2) Transgene. Radiat. Res. 159, 361–370 (2003). Oral cavity mucositis is a major toxicity of radiation therapy for head and neck cancer. In the present mouse model studies, we evaluated intraoral administration of SOD2-PL complexes 24 h before single-fraction 30-Gy irradiation for the prevention of oral cavity mucositis. Expression of the human SOD2 transgene in the oral cavity of C3H/HeNsd mice was demonstrated by nested reverse transcriptase polymerase chain reaction (RT-PCR). Mice treated intraorally with bacterial β-galactosidase gene-plasmid/liposome (LacZ-PL) or hemagglutinin (HA)-Manganese Superoxide Dismutase-plasmid/liposome (HA-SOD2-PL) demonstrated LacZ or HA-SOD2 expression, respectively, 24 h after injection. In a second strain o...
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Manganese Superoxide Dismutase sod2 inhibits radiation induced apoptosis by stabilization of the mitochondrial membrane
Radiation Research, 2002Co-Authors: Michael W Epperly, Joan Gretton, Christine A Sikora, S J Defilippi, Qimin Zhan, Donald Kufe, Joel S GreenbergerAbstract:To define the molecular pathways involved in radiation-induced apoptosis and the role of the mitochondria, 32D cl 3 hematopoietic cells and subclones overexpressing either the human Manganese Superoxide Dismutase (SOD2) transgene (1F2 and 2C6) or BCL2L1 (also known as Bcl-xl) transgene (32D-Bcl-xl) were compared for their response to radiation at the subcellular level, comparing nuclear to mitochondrial localized pathways. All cell lines showed complete detectable DNA repair by 30 min after irradiation, and clearly delayed migration of BAX and active stress-activated protein (SAP) kinases MAPK1 (also known as p38) and MAPK8 (also known as JNK1) to the mitochondria at 3 h. Radioresistant clonal lines 1F2, 2C6 and 32D-Bcl-xl showed significant decreases in mitochondrial membrane permeability, cytochrome C release, caspase 3 and poly(adenosine diphosphate-ribose) polymerase (PARP) activation at 6-12 h, and in apoptosis at 24 h. Since the nuclear-to-cytoplasm events preceding the release of cytochrome C were similar in all cell lines, and increased expression of either the SOD2 or the BCL2L1 transgene provided radiation protection, we conclude that events at the level of the mitochondria are critically involved in radiation-induced apoptosis.
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modulation of radiation induced cytokine elevation associated with esophagitis and esophageal stricture by Manganese Superoxide Dismutase plasmid liposome sod2 pl gene therapy
Radiation Research, 2001Co-Authors: Michael W Epperly, Joan Gretton, Christine A Sikora, S J Defilippi, Denny Liggitt, Gary Koe, Joel S GreenbergerAbstract:Abstract Epperly, M. W., Gretton, J. A., DeFilippi, S. J., Sikora, C. A., Liggitt, D., Koe, G. and Greenberger, J. S. Modulation of Radiation-Induced Cytokine Elevation Associated with Esophagitis and Esophageal Stricture by Manganese Superoxide Dismutase-Plasmid/Liposome (SOD2-PL) Gene Therapy. Radiation of the esophagus of C3H/HeNsd mice with 35 or 37 Gy of 6 MV X rays induces significantly increased RNA transcription for interleukin 1 (Il1), tumor necrosis factor alpha (Tnf), interferon gamma inducing factor (Ifngr), and interferon gamma (Ifng). These elevations are associated with DNA damage that is detectable by a comet assay of explanted esophageal cells, apoptosis of the esophageal basal lining layer cells in situ, and micro-ulceration leading to dehydration and death. The histopathology and time sequence of events are comparable to the esophagitis in humans that is associated with chemoradiotherapy of non-small cell lung carcinoma (NSCLC). Intraesophageal injection of clinical-grade Manganese supe...
John A Thompson - One of the best experts on this subject based on the ideXlab platform.
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peroxynitrite mediated inactivation of Manganese Superoxide Dismutase involves nitration and oxidation of critical tyrosine residues
Biochemistry, 1998Co-Authors: Lee Ann Macmillancrow, John P Crow, John A ThompsonAbstract:Previous studies from our laboratory have demonstrated that the mitochondrial protein Manganese Superoxide Dismutase is inactivated, tyrosine nitrated, and present as higher molecular mass species during human renal allograft rejection. To elucidate mechanisms whereby tyrosine modifications might result in loss of enzymatic activity and altered structure, the effects of specific biological oxidants on recombinant human Manganese Superoxide Dismutase in vitro have been evaluated. Hydrogen peroxide or nitric oxide had no effect on enzymatic activity, tyrosine modification, or electrophoretic mobility. Exposure to either hypochlorous acid or tetranitromethane (pH 6) inhibited (approximately 50%) enzymatic activity and induced the formation of dityrosine and higher mass species. Treatment with tetranitromethane (pH 8) inhibited enzymatic activity 67% and induced the formation of nitrotyrosine. In contrast, peroxynitrite completely inhibited enzymatic activity and induced formation of both nitrotyrosine and dityrosine along with higher molecular mass species. Combination of real-time spectral analysis and electrospray mass spectroscopy revealed that only three (Y34, Y45, and Y193) of the nine total tyrosine residues in Manganese Superoxide Dismutase were nitrated by peroxynitrite. Inspection of X-ray crystallographic data suggested that neighboring glutamate residues associated with two of these tyrosines may promote targeted nitration by peroxynitrite. Tyr34, which is present in the active site, appeared to be the most susceptible residue to peroxynitrite-mediated nitration. Collectively, these observations are consistent with previous results using chronically rejecting human renal allografts and provide a compelling argument supporting the involvement of peroxynitrite during this pathophysiologic condition.
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peroxynitrite mediated inactivation of Manganese Superoxide Dismutase involves nitration and oxidation of critical tyrosine residues
Biochemistry, 1998Co-Authors: Lee Ann Macmillancrow, John P Crow, John A ThompsonAbstract:Previous studies from our laboratory have demonstrated that the mitochondrial protein Manganese Superoxide Dismutase is inactivated, tyrosine nitrated, and present as higher molecular mass species during human renal allograft rejection. To elucidate mechanisms whereby tyrosine modifications might result in loss of enzymatic activity and altered structure, the effects of specific biological oxidants on recombinant human Manganese Superoxide Dismutase in vitro have been evaluated. Hydrogen peroxide or nitric oxide had no effect on enzymatic activity, tyrosine modification, or electrophoretic mobility. Exposure to either hypochlorous acid or tetranitromethane (pH 6) inhibited (approximately 50%) enzymatic activity and induced the formation of dityrosine and higher mass species. Treatment with tetranitromethane (pH 8) inhibited enzymatic activity 67% and induced the formation of nitrotyrosine. In contrast, peroxynitrite completely inhibited enzymatic activity and induced formation of both nitrotyrosine and di...
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nitration and inactivation of Manganese Superoxide Dismutase in chronic rejection of human renal allografts
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Lee Ann Macmillancrow, John P Crow, Joseph S Beckman, Jeffrey D Kerby, John A ThompsonAbstract:Inflammatory processes in chronic rejection remain a serious clinical problem in organ transplantation. Activated cellular infiltrate produces high levels of both Superoxide and nitric oxide. These reactive oxygen species interact to form peroxynitrite, a potent oxidant that can modify proteins to form 3-nitrotyrosine. We identified enhanced immunostaining for nitrotyrosine localized to tubular epithelium of chronically rejected human renal allografts. Western blot analysis of rejected tissue demonstrated that tyrosine nitration was restricted to a few specific polypeptides. Immunoprecipitation and amino acid sequencing techniques identified Manganese Superoxide Dismutase, the major antioxidant enzyme in mitochondria, as one of the targets of tyrosine nitration. Total Manganese Superoxide Dismutase protein was increased in rejected kidney, particularly in the tubular epithelium; however, enzymatic activity was significantly decreased. Exposure of recombinant human Manganese Superoxide Dismutase to peroxynitrite resulted in a dose-dependent (IC50 = 10 microM) decrease in enzymatic activity and concomitant increase in tyrosine nitration. Collectively, these observations suggest a role for peroxynitrite during development and progression of chronic rejection in human renal allografts. In addition, inactivation of Manganese Superoxide Dismutase by peroxynitrite may represent a general mechanism that progressively increases the production of peroxynitrite, leading to irreversible oxidative injury to mitochondria.
Timothy D H Bugg - One of the best experts on this subject based on the ideXlab platform.
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sphingobacterium sp t2 Manganese Superoxide Dismutase catalyzes the oxidative demethylation of polymeric lignin via generation of hydroxyl radical
ACS Chemical Biology, 2018Co-Authors: Goran M M Rashid, Xiaoyang Zhang, Vilmos Fulop, Rachael C Wilkinson, Betty Cottyn, Stephanie Baumberger, Timothy D H BuggAbstract:Sphingobacterium sp. T2 contains two extracellular Manganese Superoxide Dismutase enzymes which exhibit unprecedented activity for lignin oxidation but via an unknown mechanism. Enzymatic treatment of lignin model compounds gave products whose structures were indicative of aryl–Cα oxidative cleavage and demethylation, as well as alkene dihydroxylation and alcohol oxidation. 18O labeling studies on the SpMnSOD-catalyzed oxidation of lignin model compound guiaiacylglycerol-β-guaiacyl ether indicated that the an oxygen atom inserted by the enzyme is derived from Superoxide or peroxide. Analysis of an alkali lignin treated by SpMnSOD1 by quantitative 31P NMR spectroscopy demonstrated 20–40% increases in phenolic and aliphatic OH content, consistent with lignin demethylation and some internal oxidative cleavage reactions. Assay for hydroxyl radical generation using a fluorometric hydroxyphenylfluorescein assay revealed the release of 4.1 molar equivalents of hydroxyl radical by SpMnSOD1. Four amino acid replac...
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Sphingobacterium sp. T2 Manganese Superoxide Dismutase Catalyzes the Oxidative Demethylation of Polymeric Lignin via Generation of Hydroxyl Radical
2018Co-Authors: Goran M. M. Rashid, Xiaoyang Zhang, Rachael C Wilkinson, Betty Cottyn, Stephanie Baumberger, Vilmos Fülöp, Timothy D H BuggAbstract:Sphingobacterium sp. T2 contains two extracellular Manganese Superoxide Dismutase enzymes which exhibit unprecedented activity for lignin oxidation but via an unknown mechanism. Enzymatic treatment of lignin model compounds gave products whose structures were indicative of aryl–Cα oxidative cleavage and demethylation, as well as alkene dihydroxylation and alcohol oxidation. 18O labeling studies on the SpMnSOD-catalyzed oxidation of lignin model compound guiaiacylglycerol-β-guaiacyl ether indicated that the an oxygen atom inserted by the enzyme is derived from Superoxide or peroxide. Analysis of an alkali lignin treated by SpMnSOD1 by quantitative 31P NMR spectroscopy demonstrated 20–40% increases in phenolic and aliphatic OH content, consistent with lignin demethylation and some internal oxidative cleavage reactions. Assay for hydroxyl radical generation using a fluorometric hydroxyphenylfluorescein assay revealed the release of 4.1 molar equivalents of hydroxyl radical by SpMnSOD1. Four amino acid replacements in SpMnSOD1 were investigated, and A31H or Y27H site-directed mutant enzymes were found to show no lignin demethylation activity according to 31P NMR analysis. Structure determination of the A31H and Y27H mutant enzymes reveals the repositioning of an N-terminal protein loop, leading to widening of a solvent channel at the dimer interface, which would provide increased solvent access to the Mn center for hydroxyl radical generation
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identification of Manganese Superoxide Dismutase from sphingobacterium sp t2 as a novel bacterial enzyme for lignin oxidation
ACS Chemical Biology, 2015Co-Authors: Goran M M Rashid, Charles R Taylor, Xiaoyang Zhang, Vilmos Fulop, Timothy D H BuggAbstract:The valorization of aromatic heteropolymer lignin is an important unsolved problem in the development of a biomass-based biorefinery, for which novel high-activity biocatalysts are needed. Sequencing of the genomic DNA of lignin-degrading bacterial strain Sphingobacterium sp. T2 revealed no matches to known lignin-degrading genes. Proteomic matches for two Manganese Superoxide Dismutase proteins were found in partially purified extracellular fractions. Recombinant MnSOD1 and MnSOD2 were both found to show high activity for oxidation of Organosolv and Kraft lignin, and lignin model compounds, generating multiple oxidation products. Structure determination revealed that the products result from aryl–Cα and Cα–Cβ bond oxidative cleavage and O-demethylation. The crystal structure of MnSOD1 was determined to 1.35 A resolution, revealing a typical MnSOD homodimer harboring a five-coordinate trigonal bipyramidal Mn(II) center ligated by three His, one Asp, and a water/hydroxide in each active site. We propose th...