scholarly journals Reaction of Peroxynitrite with Mn-Superoxide Dismutase

2001 ◽  
Vol 276 (15) ◽  
pp. 11631-11638 ◽  
Author(s):  
Celia Quijano ◽  
Daniel Hernandez-Saavedra ◽  
Laura Castro ◽  
Joe M. McCord ◽  
Bruce A. Freeman ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Rate Constant ◽  
Active Site ◽  
Manganese Superoxide Dismutase ◽  
Order Rate Constant ◽  
Metal Centers ◽  
Manganese Ion ◽  
Hydroxyphenylacetic Acid

Manganese superoxide dismutase (Mn-SOD), a critical mitochondrial antioxidant enzyme, becomes inactivated and nitratedin vitroand potentiallyin vivoby peroxynitrite. Since peroxynitrite readily reacts with transition metal centers, we assessed the role of the manganese ion in the reaction between peroxynitrite and Mn-SOD. Peroxynitrite reacts with human recombinant andEscherichia coliMn-SOD with a second order rate constant of 1.0 ± 0.2 × 105and 1.4 ± 0.2 × 105m−1s−1at pH 7.47 and 37 °C, respectively. TheE. coliapoenzyme, obtained by removing the manganese ion from the active site, presents a rate constant <104m−1s−1for the reaction with peroxynitrite, whereas that of the manganese-reconstituted apoenzyme (apo/Mn) was comparable to that of the holoenzyme. Peroxynitrite-dependent nitration of 4-hydroxyphenylacetic acid was increased 21% by Mn-SOD. The apo/Mn also promoted nitration, but the apo and the zinc-substituted apoenzyme (apo/Zn) enzymes did not. The extent of tyrosine nitration in the enzyme was also affected by the presence and nature (i.e.manganese or zinc) of the metal center in the active site. For comparative purposes, we also studied the reaction of peroxynitrite with low molecular weight complexes of manganese and zinc with tetrakis-(4-benzoic acid) porphyrin (tbap). Mn(tbap) reacts with peroxynitrite with a rate constant of 6.8 ± 0.1 × 104m−1s−1and maximally increases nitration yields by 350%. Zn(tbap), on the other hand, affords protection against nitration. Our results indicate that the manganese ion in Mn-SOD plays an important role in the decomposition kinetics of peroxynitrite and in peroxynitrite-dependent nitration of self and remote tyrosine residues.

Human Mn-superoxide dismutase inactivation by peroxynitrite: a paradigm of metal-catalyzed tyrosine nitration in vitro and in vivo

Metallomics ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 679-695 ◽  
Author(s):  
Verónica Demicheli ◽  
Diego M. Moreno ◽  
Rafael Radi
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Enzyme Inactivation ◽  
Tyrosine Nitration ◽  
Post Translational Modification ◽  
Biologically Relevant ◽  
Metal Catalyzed

Nitration of human MnSOD at active site Tyr34 represents a biologically-relevant oxidative post-translational modification that causes enzyme inactivation.

scholarly journals Radioprotection In Vitro and In Vivo by Minicircle Plasmid Carrying the Human Manganese Superoxide Dismutase Transgene

2008 ◽  
Vol 19 (8) ◽  
pp. 820-826 ◽  
Author(s):  
Xichen Zhang ◽  
Michael W. Epperly ◽  
Mark A. Kay ◽  
Zhi-Ying Chen ◽  
Tracy Dixon ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Manganese Superoxide Dismutase ◽  
Manganese Superoxide

scholarly journals Activation of brain calcineurin (Cn) by Cu-Zn superoxide dismutase (SOD1) depends on direct SOD1–Cn protein interactions occurring in vitro and in vivo

2007 ◽  
Vol 405 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Abdulbaki Agbas ◽  
Dongwei Hui ◽  
Xinsheng Wang ◽  
Vekalet Tek ◽  
Asma Zaidi ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Protein Interactions ◽  
Active Site ◽  
Conformational State ◽  
Full Length ◽  
Poor Correlation ◽  
Calcineurin Activity ◽  
Human Sod1

Cn (calcineurin) activity is stabilized by SOD1 (Cu-Zn superoxide dismutase), a phenomenon attributed to protection from superoxide (O2•−). The effects of O2•− on Cn are still controversial. We found that O2•−, generated either in vitro or in vivo did not affect Cn activity. Yet native bovine, recombinant human or rat, and two chimaeras of human SOD1–rat SOD1, all activated Cn, but SOD2 (Mn-superoxide dismutase) did not affect Cn activity. There was also a poor correlation between SOD1 dismutase activity and Cn activation. A chimaera of human N-terminal SOD1 and rat C-terminal SOD1 had little detectable dismutase activity, yet stimulated Cn activity the same as full-length human or rat SOD1. Nevertheless, there was evidence that the active site of SOD1 was involved in Cn activation based on the loss of activation following chelation of Cu from the active site of SOD1. Also, SOD1 engaged in the catalysis of O2•− dismutation was ineffective in activating Cn. SOD1 activation of Cn resulted from a 90-fold decrease in phosphatase Km without a change in Vmax. A possible mechanism for the activation of Cn was identified in our studies as the prevention of Fe and Zn losses from the active site of Cn, suggesting a conformation-dependent SOD1–Cn interaction. In neurons, SOD1 and Cn were co-localized in cytoplasm and membranes, and SOD1 co-immunoprecipitated with Cn from homogenates of brain hippocampus and was present in immunoprecipitates as large multimers. Pre-incubation of pure SOD1 with Cn caused SOD1 multimer formation, an indication of an altered conformational state in SOD1 upon interaction with Cn.

Radioprotection In Vitro and In Vivo by Mini Circle Plasmid Containing the Human Manganese Superoxide Dismutase (MnSOD) Transgene

2008 ◽  
Vol 0 (ja) ◽  
pp. 081015093227032
Author(s):  
Xichen Zhang ◽  
Michael W Epperly ◽  
Mark A Kay ◽  
Tracy Smith ◽  
Darcy Franicola ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Manganese Superoxide Dismutase ◽  
Manganese Superoxide

scholarly journals Gene Therapy for Systemic or Organ Specific Delivery of Manganese Superoxide Dismutase

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1057
Author(s):  
Joel S. Greenberger ◽  
Amitava Mukherjee ◽  
Michael W. Epperly
Keyword(s):  
Gene Therapy ◽  
Superoxide Dismutase ◽  
Radiation Protection ◽  
Mammalian Cells ◽  
Manganese Superoxide Dismutase ◽  
Lessons Learned ◽  
Current Status ◽  
Manganese Superoxide

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.

scholarly journals Manganese superoxide dismutase (MnSOD) catalyzes NO-dependent tyrosine residue nitration

2005 ◽  
Vol 70 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Srdjan Stojanovic ◽  
Dragana Stanic ◽  
Milan Nikolic ◽  
Smiljana Raicevic ◽  
Mihajlo Spasic ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Manganese Superoxide Dismutase ◽  
Prolonged Exposure ◽  
In Vitro Study ◽  
Enzyme Inactivation ◽  
Tyrosine Nitration ◽  
Tyrosine Residue ◽  
Manganese Superoxide

The peroxynitrite-induced nitration of manganese superoxide dismutase (MnSOD) tyrosine residue, which causes enzyme inactivation, is well established. This led to suggestions that MnSOD nitration and inactivation in vivo, detected in various diseases associated with oxidative stress and overproduction of nitric monoxide (NO), conditions which favor peroxynitrite formation, is also caused by peroxynitrite. However, our previous in vitro study demonstrated that exposure of MnSOD to NO led to NO conversion into nitrosonium (NO+) and nitroxyl (NO?) species, which caused enzyme modifications and inactivation. Here it is reported that MnSOD is tyrosine nitrated upon exposure to NO, as well as that MnSOD nitration contributes to inactivation of the enzyme. Collectively, these observations provide a compelling argument supporting the generation of nitrating species in MnSOD exposed to NO and shed a new light on MnSOD tyrosine nitration and inactivation in vivo. This may represent a novel mechanism by which MnSOD protects cell from deleterious effects associated with overproduction of NO. However, extensive MnSOD modification and inactivation associated with prolonged exposure to NO will amplify the toxic effects caused by increased cell superoxide and NO levels.

scholarly journals Mitochondrial Sirtuin TcSir2rp3 Affects TcSODA Activity and Oxidative Stress Response in Trypanosoma cruzi

2021 ◽  
Vol 11 ◽  
Author(s):  
Leila dos Santos Moura ◽  
Vinícius Santana Nunes ◽  
Antoniel A. S. Gomes ◽  
Ana Caroline de Castro Nascimento Sousa ◽  
Marcos R. M. Fontes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Stress Response ◽  
Trypanosoma Cruzi ◽  
Conformational Changes ◽  
Manganese Superoxide Dismutase ◽  
Oxidative Stress Response ◽  
Lysine Acetylation

Trypanosoma cruzi faces a variety of environmental scenarios during its life cycle, which include changes in the redox environment that requires a fine regulation of a complex antioxidant arsenal of enzymes. Reversible posttranslational modifications, as lysine acetylation, are a fast and economical way for cells to react to environmental conditions. Recently, we found that the main antioxidant enzymes, including the mitochondrial superoxide dismutase A (TcSODA) are acetylated in T. cruzi, suggesting that protein acetylation could participate in the oxidative stress response in T. cruzi. Therefore, we investigated whether mitochondrial lysine deacetylase TcSir2rp3 was involved in the activity control of TcSODA. We observed an increased resistance to hydrogen peroxide and menadione in parasites overexpressing TcSir2rp3. Increased resistance was also found for benznidazole and nifurtimox, known to induce reactive oxidative and nitrosactive species in the parasite, associated to that a reduction in the ROS levels was observed. To better understand the way TcSir2rp3 could contributes to oxidative stress response, we analyzed the expression of TcSODA in the TcSir2rp3 overexpressing parasites and did not detect any increase in protein levels of this enzyme. However, we found that these parasites presented higher levels of superoxide dismutase activity, and also that TcSir2rp3 and TcSODA interacts in vivo. Knowing that TcSODA is acetylated at lysine residues K44 and K97, and that K97 is located at a similar region in the protein structure as K68 in human manganese superoxide dismutase (MnSOD), responsible for regulating MnSOD activity, we generated mutated versions of TcSODA at K44 and K97 and found that replacing K97 by glutamine, which mimics an acetylated lysine, negatively affects the enzyme activity in vitro. By using molecular dynamics approaches, we revealed that acetylation of K97 induces specific conformational changes in TcSODA with respect to hydrogen-bonding pattern to neighbor residues, suggesting a key participation of this residue to modulate the affinity to O2−. Taken together, our results showed for the first time the involvement of lysine acetylation in the maintenance of homeostatic redox state in trypanosomatids, contributing to the understanding of mechanisms used by T. cruzi to progress during the infection.

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