• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.849-855
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• 1994

Actively growin Excherichia coli(KCTC 1039) cells were treated with paraquat (1, 1'-dimethyl-4, 4'-bipyridili-um dichloride) by cultivating them in the presence of 1.0mM paraquat. The treatment was carried out with or without shaking to understand the effect of oxygen on paraquat action to thebacterial superoxide dismutase (SOd). By the treatment with vigorous shaking , population growth of the organism almostly stopped and specific activities of SOD of the cells drastically decreased. On contrast ot it, the herbicide showed only l limited inhibitory action on bacterial growth and SOD activity by stationary treatment. Proteins prepared from parquat-treated cells divided into two peaks by Sephacryl column chormatogrpahy, while proteins from the intact cells formed a single peak. Cytoplasmic proteins and plasma membrane proteins of intact cells formed separated three peaks by Sephadex G-75 column chormatography. respectively. Among them the second peak disappeared by paraquat treatment , while the third peak became more apparent. Fractions from the first and the third peak showed SOD activity. Paraquat was detected from the same fractions.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.700-706
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• 2000

Iron- and zinc-containing superoxide dismutase (FeZnSOD) and nickel-containing superoxide dismutase (NiSOD) are cytoplamic enzymes in Streptomyces griseus. The sodF gene coding for FeZnSOD was cloned from genomic Southern hybridization analysis with a 0.5-kb DNA probe, which was PCR-amplified with facing primers corresponding to the N-terminal amino acid of the purified FeZnSOD of S. griseus and a C-terminal region which is conserved among bacterial FeSODs and MnSODs. The sodF open reading frame (ORF) was comprised of 213 amino acid (22,430 Da), and the deduced sequence of the protein was highly homologous (86% identity) to that of FeZnSOD of Streptomyces coelicolor. The FeZnSOD expression of exponentially growing S. griseus cell was approximately doubled as the cell growth reached the early stationary phase. The growth-associated expression of FeZnSOD was mainly controlled at the transcriptional level, and the regulation was exerted through the 110 bp regulatory DNA upstream from the ATG initiation codon of the sodF gene.

• BMB Reports
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• v.30 no.1
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• pp.60-65
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• 1997

Expression of human Cu.Zn-superoxide dismutase (SOD) with activity comparable to human erythrocyte enzyme was achieved in E. coli B21(DE3) by using the pET-17b expression vector containing a T7 promoter. Recombinant human SOD was found in the cytosol of disrupted bacterial cells and represented > 25% of the total bacterial proteins. The protein produced by the E. coli cells was purified using a combination of ammonium sulfate precipitation, Sephacryl S-100 gel filtration and DEAE-Sephacel ion exchange chromatography. The recombinant Cu,Zn-SOD and human erythrocyte enzyme were compared using dismutation activity, SDS-PAGE and immunoblotting analysis. The mass of the subunits was determined to be 15,809 by using a electrospray mass spectrometer. The copper specific chelator. diethyldithiocarbamate (DOC) reacted with the recombinant Cu,Zn-SOD. At $50{\mu}M$ and $100{\mu}M$ concentrations of DOC, the dismutation activity was not inhibited for one hour but gradually reduced after one hour. This result suggests that the reaction of DOC with the enzyme occurred in two distinct phases (phase I and phase II). During phase I of this reaction, one DOC reacted with the copper center, with retention of the dismutation activity while the second DOC displaced the copper, with a loss of activity in phase II.

• Journal of Microbiology
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• v.40 no.2
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• pp.151-155
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• 2002

A Superoxide Dismutase (SOD) gene from the obligate intracellular bacterium Orientia tsutsugamushi has been cloned by using the polymerase chain reaction with degenerate oligonucleotide primers corresponding to conserved regions of known SODs. Nucleotide sequencing revealed that the predicted amino acid sequence was significantly more homologous to known iron-containing SODs (FeSOD) than to manganese-containing SODs (MnSOD). Conserved regions in bacterial FeSOD could also be seen. Isolation of the oriential SOD gene may provide an opportunity to examine its role in the intracellular survival of this bacterium.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.179-184
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• 2014

Mitigation of heavy metal toxicity by iron containing superoxide dismutase (FeSOD) of Streptomyces subrutilus P5 was investigated. For E. coli $DH5{\alpha}$, the survival rate in the presence of 0.1 mM lead ions was only 7% after 120 min; however, with the addition of $0.1{\mu}M$ of purified native FeSOD the survival rate increased to 39%. This detoxification effect was also shown with 0.01 mM copper ions (survival increased from 6% to 50%), and the effect was stronger than with the use of EDTA. E. coli M15[pREP4] producing 6xHis-tagged FeSOD was constructed, and this showed an increase in survival rates throughout the incubation time; in the presence of 0.1 mM lead ions,the final increase at 60 min was from 3% to 19%. The FeSOD absorbed about 123 g-atom lead per subunit; therefore, we suggest that FeSOD could sequestrate toxic heavy metals to enhance bacterial survival against heavy metal contamination.

• Journal of Periodontal and Implant Science
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• v.21 no.2
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• pp.194.2-194.2
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• 1991

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1500-1509
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• 2020

Drought is a major abiotic factor and has drastically reduced crop yield globally, thus damaging the agricultural industry. Drought stress decreases crop productivity by negatively affecting crop morphological, physiological, and biochemical factors. The use of drought tolerant bacteria improves agricultural productivity by counteracting the negative effects of drought stress on crops. In this study, we isolated bacteria from the rhizosphere of broccoli field located in Daehaw-myeon, Republic of Korea. Sixty bacterial isolates were screened for their growth-promoting capacity, in vitro abscisic acid (ABA), and sugar production activities. Among these, bacterial isolates YNA59 was selected based on their plant growth-promoting bacteria traits, ABA, and sugar production activities. Isolate YNA59 highly tolerated oxidative stress, including hydrogen peroxide (H₂O₂) and produces superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities in the culture broth. YNA59 treatment on broccoli significantly enhanced plant growth attributes, chlorophyll content, and moisture content under drought stress conditions. Under drought stress, the endogenous levels of ABA, jasmonic acid (JA), and salicylic acid (SA) increased; however, inoculation of YNA59 markedly reduced ABA (877 ± 22 ng/g) and JA (169.36 ± 20.74 ng/g) content, while it enhanced SA levels (176.55 ± 9.58 ng/g). Antioxidant analysis showed that the bacterial isolate YNA59 inoculated into broccoli plants contained significantly higher levels of SOD, CAT, and APX, with a decrease in GPX levels. The bacterial isolate YNA59 was therefore identified as Variovorax sp. YNA59. Our current findings suggest that newly isolated drought tolerant rhizospheric Variovorax sp. YNA59 is a useful stress-evading rhizobacterium that improved drought-stress tolerance of broccoli and could be used as a bio-fertilizer under drought conditions.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1881-1890
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• 2016

Manganese superoxide dismutase (MnSOD) is a vital enzyme that protects cells from free radicals through eliminating superoxide radicals ($O^{2-}$). Hirudin, a kind of small active peptide molecule, is one of the strongest anticoagulants that can effectively cure thrombus diseases. In this study, we fused Hirudin to the C terminus of human MnSOD with the GGGGS linker to generate a novel dual-feature fusion protein, denoted as hMnSOD-Hirudin. The hMnSOD-Hirudin gene fragment was cloned into the pET15b (SmaI, CIAP) vector, forming a recombinant pET15b-hMnSOD-Hirudin plasmid, and then was transferred into Escherichia coli strain Rosetta-gami for expression. SDS-PAGE was used to detect the fusion protein, which was expected to be about 30 kDa upon IPTG induction. Furthermore, the hMnSOD-Hirudin protein was heavily detected as a soluble form in the supernatant. The purification rate observed after Ni NTA affinity chromatography was above 95%. The hMnSOD-Hirudin protein yield reached 67.25 mg per liter of bacterial culture. The identity of the purified protein was confirmed by western blotting. The hMnSOD-Hirudin protein activity assay evinced that the antioxidation activity of the hMnSOD-Hirudin protein obtained was $2,444.0{\pm}96.0U/mg$, and the anticoagulant activity of the hMnSOD-Hirudin protein was $599.0{\pm}35.0ATU/mg$. In addition, in vitro bioactivity assay showed that the hMnSOD-Hirudin protein had no or little cytotoxicity in H9c2, HK-2, and H9 (human $CD_4{^+}$, T cell) cell lines. Transwell migration assay and invasion assay showed that the hMnSOD-Hirudin protein could suppress human lung cancer 95-D cell metastasis and invasion in vitro.

• Molecules and Cells
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• v.25 no.1
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• pp.55-63
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• 2008

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the selective death of motor neurons. Mutations in the SOD1 gene are responsible for a familial form of ALS (FALS). Although many studies suggest that mutant SOD1 proteins are cytotoxic, the mechanism is not fully understood. To investigate the role of mutant SOD1 in FALS, human SOD1 genes were fused with a PEP-1 peptide in a bacterial expression vector to produce in-frame PEP-1-SOD fusion proteins (wild type and mutants). The expressed and purified PEP-1-SOD fusion proteins were efficiently transduced into neuronal cells. Neurones harboring the A4V, G93A, G85R, and D90A mutants of PEP-1-SOD were more vulnerable to oxidative stress induced by paraquat than those harboring wild-type proteins. Moreover, neurones harboring the mutant SOD proteins had lower heat shock protein (Hsp) expression levels than those harboring wild-type SOD. The effects of the transduced SOD1 fusion proteins may provide an explanation for the association of SOD1 with FALS, and Hsps could be candidate agents for the treatment of ALS.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1209-1216
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• 2018

This study aimed to evaluate the antimicrobial activity of 2-phenylethynyl-butyltellurium (PEBT) in Escherichia coli and the relation to its pro-oxidant effect. For this, we carried out the disk diffusion test, minimum inhibitory concentration (MIC) assay, and survival curve analysis. We also measured the level of extracellular reactive oxygen species (ROS), activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and level of non-protein thiols (NPSH). PEBT at 1.28 and 0.128 mg/disk exhibited antimicrobial capability in the disk diffusion test, with an MIC value of 1.92 mg/ml, whereas PEBT at 0.96, 1.92, and 3.84 mg/ml inhibited bacterial growth after a 9-h exposure. PEBT at 3.84, 1.92, and 0.96 mg/ml increased extracellular ROS production, decreased the intracellular NPSH level, and reduced the SOD and CAT activities. Glutathione or ascorbic acid in the medium protected the bacterial cells from the antimicrobial effect of PEBT. In conclusion, PEBT exhibited antimicrobial activity against E. coli, involving the generation of ROS, oxidation of NPSH, and reduction of the antioxidant defenses in the bacterial cells.