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Clotilde Marin - One of the best experts on this subject based on the ideXlab platform.
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in vitro antileishmanial activity and Iron Superoxide Dismutase inhibition of arylamine mannich base derivatives
Parasitology, 2017Co-Authors: Alvaro Martinmontes, Clotilde Marin, Mery Santivanezveliz, Elsa Morenoviguri, Ruben Martinescolano, Carmen Jimenezmontes, Catalina Lopezgonzalez, Carmen Sanmartin, Ramon Gutierrez Sanchez, Manuel SanchezmorenoAbstract:Leishmaniasis is one of the world's most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight leishmaniasis remains a crucial goal today. With this purpose in mind, we present 20 arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of Leishmania infantum, Leishmania donovani and Leishmania braziliensis strains. Six out of the 20 Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at an IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of Iron Superoxide Dismutase inhibition. These molecules could be potential candidates for leishmaniasis chemotherapy.
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diagnosis of congenital chagas disease using an Iron Superoxide Dismutase excreted as antigen in mothers and their children during the first year of life
Pediatric Infectious Disease Journal, 2016Co-Authors: Fanny Concha Valdez, Clotilde Marin, Javier Flores Abuxapqui, Javier Escobedo Ortegon, Rocio Canas, Manuel Sánchez- MorenoAbstract:Background: Chagas disease caused by Trypanosoma cruzi is endemic in Latin America. Human infection is mainly spread by Triatominae insects. Other forms of transmission are congenital, blood transfusion and organ transplantation. Methods: Anti-T. cruzi antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) in 155 serum samples from mothers and their babies. Indirect immunofluorescence (IFA) and a commercial test were used to validate efficacy of a specific ELISA–Iron-excreted Superoxide Dismutase assay. Sera from babies were collected at 6 and 12 months, whereas maternal samples were obtained after delivery. Calostrum and umbilical cord samples were simultaneously obtained. Results: Anti-T. cruzi antibodies were detected in 8 (5.16%) mothers by ELISA-WB, in 7 (4.51%) using IFA and in 1 (0.64%) by a commercial kit. Nine (5.80%) 6-month-old children were positive by ELISA-WB and 7 (4.51%) by IFA; negative results were obtained when the commercial kit was used. At 12 month of age, 15 (9.67%) children were positive by ELISA-WB, 13 (8.38%) by IFA and 1 (0.64%) by the commercial test. Antibodies were detected in 4 mothers whose children were serologically negative. Four other mothers and their children were positive, but only one of them had detected antibodies in umbilical cord up to 12 months, thus assuming vertical transmission. Conclusions: The use of Iron-excreted Superoxide Dismutase as antigen in serologic tests for detection of T. cruzi yielded promising results as diagnostic procedure.
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An in vitro Iron Superoxide Dismutase inhibitor decreases the parasitemia levels of Trypanosoma cruzi in BALB/c mouse model during acute phase
Elsevier, 2015Co-Authors: Francisco Olmo, Manuel Sánchez-moreno, Kristína Urbanová, Maria Jose Rosales, Ruben Martín-escolano, Clotilde MarinAbstract:In order to identify new compounds to treat Chagas disease during the acute phase with higher activity and lower toxicity than the reference drug benznidazole (Bz), two hydroxyphthalazine derivative compounds were prepared and their trypanocidal effects against Trypanosoma cruzi were evaluated by light microscopy through the determination of IC50 values. Cytotoxicity was determined by flow cytometry assays against Vero cells. In vivo assays were performed in BALB/c mice, in which the parasitemia levels were quantified by fresh blood examination; the assignment of a cure was determined by reactivation of blood parasitemia levels after immunosuppression. The mechanism of action was elucidated at metabolic and ultra-structural levels, by 1H NMR and TEM studies. Finally, as these compounds are potentially capable of causing oxidative damage in the parasites, the study was completed, by assessing their activity as potential Iron Superoxide Dismutase (Fe-SOD) inhibitors. High-selectivity indices observed in vitro were the basis of promoting one of the tested compounds to in vivo assays. The tests on the murine model for the acute phase of Chagas disease showed better parasitemia inhibition values than those found for Bz. Compound 2 induced a remarkable decrease in the reactivation of parasitemia after immunosuppression. Compound 2 turned out to be a great inhibitor of Fe-SOD. The high antiparasitic activity and low toxicity together with the modest costs for the starting materials render this compound an appropriate molecule for the development of an affordable anti-Chagas agent
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synthetic single and double aza scorpiand macrocycles acting as inhibitors of the antioxidant enzymes Iron Superoxide Dismutase and trypanothione reductase in trypanosoma cruzi with promising results in a murine model
RSC Advances, 2014Co-Authors: F J Olmo, Clotilde Marin, Kristína Urbanová, Maria Paz Clares, Jorge Gonzalez, Mario Inclan, Conxa Soriano, Roberto Tejero, M J Rosales, R L KrauthsiegelAbstract:The anti-chagasic activity of a series of eleven derivatives of aza-scorpiand-like macrocycles, some of them newly synthesised, was assayed. The four compounds with the best selectivity indices in vitro were subjected to in vivo assays. Tests in a murine model of the acute phase of Chagas disease showed a two-fold reduction in parasitaemia compared to that with benznidazole. Furthermore, compounds 7 and 11, with 4-pyridine and phenanthroline substituents in the lateral chain, caused a remarkable decrease in parasitaemia reactivation during the chronic phase after inducing immunosuppression in mice. These activity studies were complemented by measuring their inhibitory effect towards the antioxidant parasite-specific enzymes, Iron Superoxide Dismutase (Fe-SOD) and trypanothione reductase, the metabolites excreted after treatment and ultrastructural alterations. The ability of the selected macrocycles to complex with Fe(II) and Fe(III) was studied using potentiometric methods. Detailed molecular dynamics studies provided interesting pointers about the way in which the compounds approach and modify the active centre of Fe-SOD. The activity, low toxicity, stability, low cost of the starting materials and straightforward synthesis make these compounds appropriate molecules for the development of affordable anti-chagasic agents.
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Identification of excreted Iron Superoxide Dismutase for the diagnosis of Phtytomonas
2013Co-Authors: Clotilde Marin, Isabel Rodríguez-gonzález, Manuel Sánchez- MorenoAbstract:An excreted Iron Superoxide Dismutase (FeSODe) of pI 3.6 with a molecular weight of 28-30 kDa was detected in the in vitro culture of Phytomonas isolated from Euphorbia characias (SODeCHA) and from Lycopersicon esculentum (SODeTOM), in Grace’s medium without serum. These FeSODe excreted into the medium had immunogenic capacity: the positivity of the anti-SODeCHA serum persisted to a dilution of 1/30,000, and for the anti-SODeTOM to 1/ 10,000 by Western blot. In addition, cross reaction was detected between the anti-SODe serum of Phytomonas isolated from E. characias against SODeTOM, and the anti-SODe serum from L. esculentum with SODeCHA. This characteristic offers the possibility of its use to diagnose plant trypanosomatids. The validation of the test was confirmed by experimental inoculation of tomato fruits with Phytomonas isolated from L. esculentum. At 7, 10, 15, and 21 days post infection, it was possible to detect the presence of the parasites with the anti-SODe serum of Phytomonas isolated from L. esculentum at a dilution of 1/250. These serological results were confirmed by visualization of the parasites by optical microscopy. The data of this study confirm that the SOD is sufficient to identify a trypanosomatid isolated from plants as belonging to the genus Phytomonas. Key words: Superoxide Dismutase- immunogenicity- molecular tool- Phytomonas spp. Trypanosomatids belonging to the genus Phytomonas are fairly common in the latex, phloem, fruit sap, seed albumen
Thomas C Brunold - One of the best experts on this subject based on the ideXlab platform.
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structural spectroscopic and computational characterization of the azide adduct of fe iii 2 6 diacetylpyridinebis semioxamazide a functional analogue of Iron Superoxide Dismutase
Inorganic Chemistry, 2013Co-Authors: Craig T Gutman, Ilia A Guzei, Thomas C BrunoldAbstract:We have prepared and thoroughly characterized, using X-ray crystallographic, spectroscopic, and computational methods, the diazide adduct of [Fe(III)(dapsox)(H2O)2](+) [dapsox = 2,6-diacetylpyridinebis(semioxamazide)], (1), a low-molecular weight, functional analogue of Iron Superoxide Dismutase (FeSOD). The X-ray crystal structure of the dimeric form of 1, (Na[Fe(III)(dapsox)(N3)2]·DMF)2 (2) shows two axially coordinated, symmetry inequivalent azides with differing Fe-N3 bond lengths and Fe-N-N2 bond angles. This inequivalence of the azide ligands likely reflects the presence of an interdimer hydrogen bonding interaction between a dapsox NH group and the coordinated nitrogen of one of the two azide ligands. Resonance Raman (rR) data obtained for frozen aqueous solution and solid-state samples of 2 indicate that the azides remain inequivalent in solution, suggesting that one of the azide ligands of 1 engages in an intermolecular hydrogen bonding interaction with a water molecule. Density functional theory (DFT) and time-dependent DFT calculations have been used to study two different computational models of 1, one using coordinates taken from the X-ray crystal structure of 2, and the other generated via DFT geometry optimization. An evaluation of these models on the basis of electronic absorption, magnetic circular dichroism, and rR data indicates that the crystal structure based model yields a more accurate electronic structure description of 1, providing further support for the proposed intermolecular hydrogen bonding of 1 in the solid state and in solution. An analysis of the experimentally validated DFT results for this model reveals that the azides have both σ- and π-bonding interactions with the Fe(III) center and that more negative charge is located on the Fe-bound, rather than on the terminal, nitrogen atom of each azide. These observations are reminiscent of the results previously reported for the azide adduct of FeSOD and provide clues regarding the origin of the high catalytic activity of Fe-dapsox for Superoxide disproportionation.
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geometric and electronic structures of manganese substituted Iron Superoxide Dismutase
Inorganic Chemistry, 2013Co-Authors: Timothy A Jackson, Craig T Gutman, James Maliekal, Annefrances Miller, Thomas C BrunoldAbstract:The active-site structures of the oxidized and reduced forms of manganese-substituted Iron Superoxide Dismutase (Mn(Fe)SOD) are examined, for the first time, using a combination of spectroscopic and computational methods. On the basis of electronic absorption, circular dichroism (CD), magnetic CD (MCD), and variable-temperature variable-field MCD data obtained for oxidized Mn(Fe)SOD, we propose that the active site of this species is virtually identical to that of wild-type manganese SOD (MnSOD), with both containing a metal ion that resides in a trigonal bipyramidal ligand envIronment. This proposal is corroborated by quantum mechanical/molecular mechanical (QM/MM) computations performed on complete protein models of Mn(Fe)SOD in both its oxidized and reduced states and, for comparison, wild-type (WT) MnSOD. The major differences between the QM/MM optimized active sites of WT MnSOD and Mn(Fe)SOD are a smaller (His)N–Mn–N(His) equatorial angle and a longer (Gln146(69))NH···O(sol) H-bond distance in the me...
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spectroscopic and computational studies of a small molecule functional mimic of Iron Superoxide Dismutase Iron 2 6 diacetylpyridinebis semioxamazide
Inorganic Chemistry, 2012Co-Authors: Craig T Gutman, Thomas C BrunoldAbstract:Iron 2,6-diacetylpyridinebis(semioxamazide) (Fe(dapsox)) is a heptacoordinate pentagonal bipyramidal, functional mimic of Iron-dependent Superoxide Dismutase that has been well-characterized on the...
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spectroscopic and computational investigation of second sphere contributions to redox tuning in escherichia coli Iron Superoxide Dismutase
Inorganic Chemistry, 2008Co-Authors: Laurie E Grove, Annefrances Miller, Emine Yikilmaz, Juan Xie, Thomas C BrunoldAbstract:In Fe- and Mn-dependent Superoxide Dismutases (SODs), second-sphere residues have been implicated in precisely tuning the metal ion reduction potential to maximize catalytic activity (Vance, C. K.; Miller, A.-F. J. Am. Chem. Soc. 1998, 120, 461–467). In the present study, spectroscopic and computational methods were used to characterize three distinct Fe-bound SOD species that possess different second-coordination spheres and, consequently, Fe3+/2+reduction potentials that vary by ∼1 V, namely, FeSOD, Fe-substituted MnSOD (Fe(Mn)SOD), and the Q69E FeSOD mutant. Despite having markedly different metal ion reduction potentials, FeSOD, Fe(Mn)SOD, and Q69E FeSOD exhibit virtually identical electronic absorption, circular dichroism, and magnetic circular dichroism (MCD) spectra in both their oxidized and reduced states. Likewise, variable-temperature, variable-field MCD data obtained for the oxidized and reduced species do not reveal any significant electronic, and thus geometric, variations within the Fe liga...
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spectroscopic and computational study of a non heme Iron fe no 7 system exploring the geometric and electronic structures of the nitrosyl adduct of Iron Superoxide Dismutase
Journal of the American Chemical Society, 2003Co-Authors: Timothy A Jackson, Emine Yikilmaz, And Annefrances Miller, Thomas C BrunoldAbstract:Like many non-heme Iron enzymes, reduced Iron Superoxide Dismutase (Fe2+SOD) reacts with nitric oxide (NO) to yield an {Fe−NO}7 system. Electron paramagnetic resonance (EPR) data obtained for this Fe−NO adduct of FeSOD (NO−FeSOD) exhibit two rhombic S = 3/2 signals of comparable population; E/D = 0.128 (42%) and 0.154 (58%). While similar results were previously reported for NO−FeSOD [Niederhoffer, E. C.; Fee, J. A.; Papaefthymiou, V.; Munck, E. Magnetic Resonance Studies Involving Iron Superoxide Dismutase from Escherichia coli. Isotope and Nuclear Chemistry Division Annual Report; Los Alamos National Laboratory: Los Alamos, NM, 1987], detailed geometric and electronic structure descriptions of these {Fe−NO}7 systems had not yet been developed. Therefore, in addition to EPR spectroscopy, we have used electronic absorption, magnetic circular dichroism (MCD), variable-temperature, variable-field MCD, and resonance Raman spectroscopies to determine ground-state spin Hamiltonian parameters, electronic trans...
Manuel Sanchezmoreno - One of the best experts on this subject based on the ideXlab platform.
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in vitro antileishmanial activity and Iron Superoxide Dismutase inhibition of arylamine mannich base derivatives
Parasitology, 2017Co-Authors: Alvaro Martinmontes, Clotilde Marin, Mery Santivanezveliz, Elsa Morenoviguri, Ruben Martinescolano, Carmen Jimenezmontes, Catalina Lopezgonzalez, Carmen Sanmartin, Ramon Gutierrez Sanchez, Manuel SanchezmorenoAbstract:Leishmaniasis is one of the world's most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight leishmaniasis remains a crucial goal today. With this purpose in mind, we present 20 arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of Leishmania infantum, Leishmania donovani and Leishmania braziliensis strains. Six out of the 20 Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at an IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of Iron Superoxide Dismutase inhibition. These molecules could be potential candidates for leishmaniasis chemotherapy.
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in vitro leishmanicidal activity of imidazole or pyrazole based benzo g phthalazine derivatives against leishmania infantum and leishmania braziliensis species
Journal of Antimicrobial Chemotherapy, 2012Co-Authors: Clotilde Marin, Manuel Sanchezmoreno, Francisco Olmo, Inmaculada Ramirezmacias, Fernando Gomezcontreras, Pilar Navarro, Carmen Cano, Maria J R Yunta, Ana M Sanz, Lucrecia CampayoAbstract:OBJECTIVES: To evaluate the in vitro leishmanicidal activity of imidazole-based (1-4) and pyrazole-based (5-6) benzo[g]phthalazine derivatives against Leishmania infantum and Leishmania braziliensis. METHODS: The in vitro activity of compounds 1-6 was assayed on extracellular promastigote and axenic amastigote forms, and on intracellular amastigote forms of the parasites. Infectivity and cytotoxicity tests were performed on J774.2 macrophage cells using meglumine antimoniate (Glucantime) as the reference drug. The mechanisms of action were analysed by Iron Superoxide Dismutase (Fe-SOD) and copper/zinc Superoxide Dismutase (CuZn-SOD) inhibition, metabolite excretion and transmission electronic microscopy (TEM). RESULTS: Compounds 1-6 were more active and less toxic than meglumine antimoniate. Data on infection rates and amastigote mean numbers showed that 2, 4 and 6 were more active than 1, 3 and 5 in both L. infantum and L. braziliensis. The inhibitory effect of these compounds on the antioxidant enzyme Fe-SOD of promastigote forms of the parasites was remarkable, whereas inhibition of human CuZn-SOD was negligible. The ultrastructural alterations observed in treated promastigote forms confirmed the greater cell damage caused by the most active compounds 2, 4 and 6. The modifications observed by (1)H-NMR in the nature and amounts of catabolites excreted by the parasites after treatment with 1-6 suggested that the catabolic mechanisms could depend on the structure of the side chains linked to the benzo[g]phthalazine moiety. CONCLUSIONS: All the compounds assayed were active in vitro against the two Leishmania species and were less toxic against mammalian cells than the reference drug, but the monosubstituted compounds were significantly more effective and less toxic than their disubstituted counterparts.
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an Iron Superoxide Dismutase antigen based serological screening of dogs indicates their potential role in the transmission of cutaneous leishmaniasis and trypanosomiasis in yucatan mexico
Vector-borne and Zoonotic Diseases, 2011Co-Authors: Silvia S Longoni, Clotilde Marin, Carlos H Sauriarceo, Angeles Lopezcespedes, R I Rodriguezvivas, Noelia Villegas, Javier Escobedoortegon, Mario Barreraperez, Manuel Emilio Boliogonzalez, Manuel SanchezmorenoAbstract:Abstract An increasing number of studies have reported high infection rates for American cutaneous leishmaniasis in dogs, which have thus been proposed as the reservoir host. Canine leishmaniasis is widespread in different states in Mexico, where a number of Leishmania species have been isolated from dogs. In the present study, the detection of different Leishmania species is described in stray dogs from two localities, namely Tulum and Celestun on the Yucatan Peninsula (Mexico). The use of Iron-Superoxide Dismutase excreted by the parasites as the antigen fraction and enzyme-linked immunosorbent assay and western blot tests allowed us to confirm the presence of at least three species of Leishmania (Le. mexicana, Le. braziliensis, and Le. panamensis), some of which are reported for the first time in this species. In addition to a high prevalence of Le. mexicana and Le. braziliensis, and to a lesser degree, Le. panamensis, there is a significant prevalence of Trypanosoma cruzi, suggesting that the dog may ...
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efficient inhibition of Iron Superoxide Dismutase and of trypanosoma cruzi growth by benzo g phthalazine derivatives functionalized with one or two imidazole rings
Journal of Medicinal Chemistry, 2008Co-Authors: Ana M Sanz, Manuel Sanchezmoreno, Fernando Gomezcontreras, Pilar Navarro, Carmen Cano, Samira Boutalebcharki, Jose Campuzano, Mercedes Pardo, Antonio Osuna, Maria J R YuntaAbstract:The synthesis and trypanosomatic behavior of a new series of 1,4-bis(alkylamino)benzo[g]phthalazines 1- 4 containing the biologically significant imidazole ring are reported. In vitro antiparasitic activity against Trypanosoma cruzi epimastigotes is remarkable, especially for compound 2, whereas toxicity against Vero cells is very low. Conversion of epimastigotes to metacyclic forms in the presence of the tested compounds causes significant decreases in the amastigote and trypomastigote numbers. Fe-SOD inhibition is noteworthy, whereas effect on human Cu/Zn-SOD is negligible.
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the use of an excreted Superoxide Dismutase in an elisa and western blotting for the diagnosis of leishmania leishmania infantum naturally infected dogs
Parasitology Research, 2007Co-Authors: Clotilde Marin, Silvia S Longoni, Hector Mateo, J A De Diego, Jose Maria Alunda, Gloria Minaya, Manuel SanchezmorenoAbstract:An excreted Iron Superoxide Dismutase of pI 3.75 and a molecular mass of approximately 25 kDa was partially purified by QAE Sephadex ion-exchange chromatography from the in vitro culture of Leishmania (Leishmania) infantum. This enzyme was detected by enzyme-linked immunosorbent assay and Western blot of anti-L. infantum antibodies in dog serum. For the determination of the sensitivity and specificity of this protein, the results using the complete-parasite antigen fraction were taken as references. For this, 39 sera were assayed in dogs from different Spanish provinces. By Western blot, at a dilution of 1:250, 82% of the sera were positive when Superoxide Dismutase excreted was used as the antigen, against 56.4% positivity when the complete parasite was used as the antigen. These findings support the results of a previous study, indicating that the Superoxide Dismutase excreted can be useful in diagnosing L. (L.) infantum.
Craig T Gutman - One of the best experts on this subject based on the ideXlab platform.
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structural spectroscopic and computational characterization of the azide adduct of fe iii 2 6 diacetylpyridinebis semioxamazide a functional analogue of Iron Superoxide Dismutase
Inorganic Chemistry, 2013Co-Authors: Craig T Gutman, Ilia A Guzei, Thomas C BrunoldAbstract:We have prepared and thoroughly characterized, using X-ray crystallographic, spectroscopic, and computational methods, the diazide adduct of [Fe(III)(dapsox)(H2O)2](+) [dapsox = 2,6-diacetylpyridinebis(semioxamazide)], (1), a low-molecular weight, functional analogue of Iron Superoxide Dismutase (FeSOD). The X-ray crystal structure of the dimeric form of 1, (Na[Fe(III)(dapsox)(N3)2]·DMF)2 (2) shows two axially coordinated, symmetry inequivalent azides with differing Fe-N3 bond lengths and Fe-N-N2 bond angles. This inequivalence of the azide ligands likely reflects the presence of an interdimer hydrogen bonding interaction between a dapsox NH group and the coordinated nitrogen of one of the two azide ligands. Resonance Raman (rR) data obtained for frozen aqueous solution and solid-state samples of 2 indicate that the azides remain inequivalent in solution, suggesting that one of the azide ligands of 1 engages in an intermolecular hydrogen bonding interaction with a water molecule. Density functional theory (DFT) and time-dependent DFT calculations have been used to study two different computational models of 1, one using coordinates taken from the X-ray crystal structure of 2, and the other generated via DFT geometry optimization. An evaluation of these models on the basis of electronic absorption, magnetic circular dichroism, and rR data indicates that the crystal structure based model yields a more accurate electronic structure description of 1, providing further support for the proposed intermolecular hydrogen bonding of 1 in the solid state and in solution. An analysis of the experimentally validated DFT results for this model reveals that the azides have both σ- and π-bonding interactions with the Fe(III) center and that more negative charge is located on the Fe-bound, rather than on the terminal, nitrogen atom of each azide. These observations are reminiscent of the results previously reported for the azide adduct of FeSOD and provide clues regarding the origin of the high catalytic activity of Fe-dapsox for Superoxide disproportionation.
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geometric and electronic structures of manganese substituted Iron Superoxide Dismutase
Inorganic Chemistry, 2013Co-Authors: Timothy A Jackson, Craig T Gutman, James Maliekal, Annefrances Miller, Thomas C BrunoldAbstract:The active-site structures of the oxidized and reduced forms of manganese-substituted Iron Superoxide Dismutase (Mn(Fe)SOD) are examined, for the first time, using a combination of spectroscopic and computational methods. On the basis of electronic absorption, circular dichroism (CD), magnetic CD (MCD), and variable-temperature variable-field MCD data obtained for oxidized Mn(Fe)SOD, we propose that the active site of this species is virtually identical to that of wild-type manganese SOD (MnSOD), with both containing a metal ion that resides in a trigonal bipyramidal ligand envIronment. This proposal is corroborated by quantum mechanical/molecular mechanical (QM/MM) computations performed on complete protein models of Mn(Fe)SOD in both its oxidized and reduced states and, for comparison, wild-type (WT) MnSOD. The major differences between the QM/MM optimized active sites of WT MnSOD and Mn(Fe)SOD are a smaller (His)N–Mn–N(His) equatorial angle and a longer (Gln146(69))NH···O(sol) H-bond distance in the me...
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spectroscopic and computational studies of a small molecule functional mimic of Iron Superoxide Dismutase Iron 2 6 diacetylpyridinebis semioxamazide
Inorganic Chemistry, 2012Co-Authors: Craig T Gutman, Thomas C BrunoldAbstract:Iron 2,6-diacetylpyridinebis(semioxamazide) (Fe(dapsox)) is a heptacoordinate pentagonal bipyramidal, functional mimic of Iron-dependent Superoxide Dismutase that has been well-characterized on the...
Vincenzo Bocchini - One of the best experts on this subject based on the ideXlab platform.
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Iron Superoxide Dismutase from the archaeon sulfolobus solfataricus analysis of structure and thermostability
Journal of Molecular Biology, 1999Co-Authors: Thomas Ursby, B S Adinolfi, Salam Alkaradaghi, E De Vendittis, Vincenzo BocchiniAbstract:The crystal structure of Superoxide Dismutase (SOD) from the hyper thermophile Sulfolobus solfataricus has been determined at 2.3 A resolution by molecular replacement and refined to a crystallographic R-factor of 16.8 % (Rfree 19.8 %). The crystals belong to the space group C2 (a = 76.3 A, b = 124.3 A,c = 60.3 A, β = 128.8°) with two identical monomers in the asymmetric unit. The monomer has a molecular weight of 24 kDa and consists of 210 amino acid residues of which 205 are visible in the electron density map. The overall fold of the monomer of S. solfataricus SOD is similar to that of the other known Fe or Mn-SODs. S. solfataricus SOD forms a very compact tetramer of a type similar to that of SOD from the hyperthermophile Aquifex pyrophilus. Both structures show an elevated number of inter-subunit ion-pairs compared with the mesophilic SOD from Mycobacterium tuberculosis and the thermophilic SOD from Thermus thermophilus. However, in contrast to the A. pyrophilus SOD structure, the number of intra-subunit ion-pairs as well as inter-subunit hydrogen bonds is not higher than in the compared mesophilic and thermophilic SOD structures. The electron density also revealed an unexpected and unusual covalent modification of a conserved tyrosine in the active site. Its involvement in the specific activity of the enzyme is discussed.
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Iron Superoxide Dismutase from the archaeon sulfolobus solfataricus average hydrophobicity and amino acid weight are involved in the adaptation of proteins to extreme envIronments
Biochimica et Biophysica Acta, 1997Co-Authors: Antonio Russo, Mariorosario Masullo, Rosario Rullo, Gianpaolo Nitti, Vincenzo BocchiniAbstract:Abstract The Iron–Superoxide Dismutase in the thermoacidophilic archaeon Sulfolobus solfataricus has a homodimeric structure with a metal content of 0.7 atom of Iron per subunit. The enzyme is insensitive to cyanide inhibition, sensitive to inactivation by H 2 O 2 and is the most heat resistant SOD known so far being its half-life 2 h at 100°C. Its primary structure was determined by a profitable combination of advanced mass spectrometry and automated sequence analysis of peptides obtained after cleavage of the purified protein. The enzyme subunit is composed of 210 amino acid residues accounting for a relative molecular mass of 24 112. It does not contain cysteine residues and has a high average of both hydrophobicity and amino acid weight. Vice versa, the hydrophobicity is lower in halophilic SODs. Therefore, it seems that the average hydrophobicity is involved in the adaptation of proteins to extreme envIronments. The multiple alignment of the primary structure of archaeal and thermophilic eubacterial SODs indicated that archaeal SODs evolved separately from the thermophilic eubacterial SODs and that halophiles originated from a gene different from that of thermophilic archaea.
