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 biological role and the regulation of superoxide dismutase (SOD) in E. coli have been investigated using genetics. Cloning of both E. coli SOD genes permitted construction of mutants completely lacking SOD. The conditional oxygen sensitivity of those mutants, together with their increased mutation rate, demonstrated the essential biological role of SOD. SOD-deficient mutants constitute a powerful tool to assess a possible role of O-2 or SOD in biological processes. Complementation of their deficiencies by the expression of SOD originating from a different organism is used for screening libraries for SOD genes of other species. Regulation of MnSOD has been studied using protein and operon fusions with the lactose operon, and isolating regulation mutants. These studies reveal multiregulation of MnSOD including response to the superoxide mediated oxidative stress and response to variations of the intracellular redox state induced by metabolic changes.
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PMID:The molecular genetics of superoxide dismutase in E. coli. 207 Oct 41

1. A number of dietary sugars are known to mediate the effects of copper deficiency. The effects of lactose (compared with sucrose) and a dietary Cu deficiency on hepatic and cardiac antioxidant enzyme activities and tissue mineral element status were investigated in the rat. 2. Groups (n 6) of male weanling Wistar rats were provided ad lib. with deionized water and diets containing sucrose (580 g/kg) or sucrose and lactose (387 g/kg and 193 g/kg respectively) with either control (12.0 mg/kg) or deficient (1.5 mg/kg) quantities of Cu for 77 d. 3. Animals consuming the low-Cu diets exhibited significantly decreased tissue Cu levels (P less than 0.01), hepatic and cardiac cytochrome c oxidase (EC 1.9.3.1, CCO) activities (P less than 0.01 and P less than 0.001 respectively) and hepatic Cu-zinc superoxide dismutase (EC 1.15.1.1, CuZnSOD) activity (P less than 0.05). The low-Cu diets also significantly decreased cardiac manganese superoxide dismutase (EC 1.15.1.1, MnSOD), catalase (EC 1.11.1.6) and glutathione peroxidase (EC 1.11.1.9, GSH-Px) activities (P less than 0.01, P less than 0.05 and P less than 0.001 respectively). 4. Hepatic Mn was significantly increased in both lactose-fed (P less than 0.001) and Cu-deficient (P less than 0.01) animals. These increases were unrelated to hepatic MnSOD activity. Cardiac Zn was significantly (P less than 0.01) increased in Cu-deficient animals. 5. Lactose feeding resulted in significantly increased cardiac CCO activity (P less than 0.001) but significantly decreased hepatic CuZnSOD (P less than 0.05), catalase (P less than 0.01) and GSH-Px (P less than 0.001) activities. 6. The activities of lactose dehydrogenase (EC 1.1.1.27, LDH) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PDH) were found to be significantly (P less than 0.05 and P less than 0.01 respectively) increased in Cu-deficient animals and G6PDH activity was significantly (P less than 0.01) decreased as a result of lactose consumption. 7. The observed changes in antioxidant enzyme activities associated with both Cu deficieny and lactose consumption may have important implications for the development of free radical mediated cell damage. However, no significant differences in either hepatic or cardiac levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation, were found.
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PMID:Effects of copper deficiency on hepatic and cardiac antioxidant enzyme activities in lactose- and sucrose-fed rats. 253 51

Superoxide-mediated oxidative stress initiates a chain of events resulting in numerous cellular injuries. We have used genetics and E. coli to investigate the role and regulation of superoxide dismutase (SOD) and its relationship with the other constituents of the oxygen toxicity defence system. Structural SOD genes have been cloned and sequenced, permitting us to refine structural analysis and to isolate SOD-deficient mutants. The conditional oxygen sensitivity of these mutants, together with their increased mutation rate, demonstrated the essential biological role of SOD. Furthermore the complementation of SOD-lacking E. coli deficiencies by introducing a plasmid containing the gene encoding the human SOD supported the proposal that superoxide dismutation is the physiological function of SOD. Regulation of the MnSOD, through which the global SOD level in E. coli is modulated, has been studied using operon and protein fusions with the lactose operon, and led to the conclusion of a multicontrol of MnSOD. Isolation and characterization of regulation mutants are in progress, with the aim of identifying effectors and targets involved in the response to superoxide-mediated oxidative stress.
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PMID:The molecular genetics of superoxide dismutase in E. coli. An approach to understanding the biological role and regulation of SODS in relation to other elements of the defence system against oxygen toxicity. 268 1