Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04179 (MnSOD)
 2,777 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The X-ray structure of the tetrameric iron-dependent superoxide dismutase from Mycobacterium tuberculosis has been refined to an R-factor of 0.167 and a correlation coefficient of 0.954 at 2.0 A resolution. The crystals are monoclinic P2(1) and have four subunits related by strong non-crystallographic 222 (or D2) symmetry in the asymmetric unit. 198 of the 207 amino acids of each subunit are defined by the electron density which shows that they adopt the conserved fold of other iron- or manganese-dependent SODs. The structure can be divided into two domains, the N-terminal domain involving an extended region followed by two projecting antiparallel alpha-helices, and the C-terminal domain containing four more helical segments with a three-stranded antiparallel beta-sheet inserted sequentially between the fourth and fifth helices. The catalytic iron is co-ordinated by five ligands: three histidines (residues 28, 76 and 164), one aspartate (160) and a solvent molecule. The inferred positions of protons at the active site are consistent with the solvent ligand being a hydroxide ion. This ligand interacts with His145 in the Mycobacterium tuberculosis SOD. In the highly homologous Mycobacterium leprae Mn-SOD, the histidine is replaced by glutamine, this being the only significant residue difference within 10 A of the Fe3+. The nature of the amino acid at this position may influence the metal ion specificity of these enzymes. The subunits of the Mycobacterium tuberculosis SOD associate by polar contacts to form dimers, which closely resemble those of other dimeric or tetrameric Fe- or Mn-SODs. However, the dimer-dimer interactions within the tetramer are novel, being dominated by dimerisation of the 144 to 152 loop regions which connect the outer two beta-strands of the three-membered beta-sheet. This contrasts strongly with the other tetrameric Fe- or Mn-SODs where the dimer-dimer association is dominated by the projecting alpha alpha-turn in the N-terminal domain.
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PMID:X-ray structure analysis of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.0 Angstroms resolution reveals novel dimer-dimer interactions. 787 74

This study describes the purification and immunochemical characterization of a major 23 kDa cytosolic protein antigen of the vaccine candidate Mycobacterium habana (TMC 5135). The 23 kDa protein alone was salted out from the cytosol at an ammonium sulfate saturation of 80-95%. It represented about 1.5% of the total cytosolic protein, appeared glycosylated by staining with periodic acid/Schiff's reagent, and showed a pl of approximately 5.3. Its native molecular mass was determined as approximately 48 kDa, suggesting a homodimeric configuration. Immunoblotting with the WHO-IMMLEP/IMMTUB mAbs mc5041 and IT61 and activity staining after native PAGE established its identity as a mycobacterial superoxide dismutase (SOD) of the Fe/Mn type. The sequence of the 18 N-terminal amino acids, which also contained the binding site for mc5041, showed a close resemblance, not only with the reported deduced sequences of Mycobacterium leprae and Mycobacterium tuberculosis Fe/MnSODs, but also with human MnSOD. In order to study its immunopathological relevance, the protein was subjected to in vivo and in vitro assays for T cell activation. It induced, in a dose-related manner, skin delayed hypersensitivity in guinea-pigs and lymphocyte proliferation in BALB/c mice primed with M. habana. Most significantly, it also induced lymphocyte proliferative responses, in a manner analogous to M. Ieprae, in human subjects comprising tuberculoid leprosy patients and healthy contacts.
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PMID:A major T-cell-inducing cytosolic 23 kDa protein antigen of the vaccine candidate Mycobacterium habana is superoxide dismutase. 870 77

The production of reactive nitrogen intermediates (RNI) by macrophages is critical to host defence, particularly for exerting the bactericidal and tumoricidal properties. Nitric oxide (NO) were measured in the peripheral blood-derived monocytes/macrophages of normal and leprosy patients (BT/TT and BL/LL) in the presence and absence of 'tuftsin' as a function of in vitro culture age (on 1, 3, 7 days). Macrophages from both groups of leprosy patients were able to produce NO during the unstimulated state but only BL/LL macrophages could be activated by tuftsin to produce significantly high levels of NO. This increase was highest on day 1, then gradually decreased with in vitro culture age. Surprisingly, tuftsin was unable to enhance the NO production in normal macrophages above the basal level. Further, normal and BT/TT macrophages had only Cu-Zn derived superoxide dismutase (SOD) activity whereas BL/LL cultures has Cu-Zn and Mn derived SOD activity. These studies indicate that in BL/LL cultures: a, apart from tuftsin, some additional signal is required to activate nitric oxide synthase (NOS) gene for NO production; and b, Mn-SOD produced by Mycobacterium leprae is playing a defensive role against toxic-free radicals. The final outcome of this mechanism is the survival of M. leprae inside the macrophages.
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PMID:Release of reactive nitrogen intermediates from the peripheral blood-derived monocytes/macrophages of leprosy patients stimulated in vitro by tuftsin. 912 27

A cytosolic superoxide dismutase (SOD) was purified and characterized from a fast-growing Mycobacterium sp. strain JC1 DSM 3803 grown on methanol. The native molecular weight of the purified SOD was estimated to be 48 kDa. SDS-PAGE revealed a subunit of 23 kDa, indicating that the enzyme is a homodimer. The enzyme activity was inhibited by H(2)O(2) and azide. The purified SOD contained 1.12 and 0.56 g-atom of Mn and Fe per mol of enzyme, respectively, suggesting that it may be a Fe/Mn cambialistic SOD. The apo-SOD reconstitution study revealed that Mn salts were more specific than Fe salts in the SOD activity. The gene encoding the SOD was identified from the JC1 cosmid genomic library by PCR screening protocol. The cloned gene, sodA, had an open reading frame (ORF) of 624 nt, encoding a protein with a calculated molecular weight of 22,930 Da and pi of 5.33. The deduced SodA sequence exhibited 97.6% identity with that of Mycobacterium fortuitum Mn-SOD and clustered with other mycobacterial Mn-SODs. A webtool analysis on the basis of SOD sequence and structure homologies predicted the SOD as a tetrameric Mn-SOD, suggesting that the protein is a dimeric Mn-SOD having tetramer-specific sequence and structure characteristics.
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PMID:Molecular cloning, purification, and characterization of a superoxide dismutase from a fast-growing Mycobacterium sp. Strain JC1 DSM 3803. 2171 25