A molecular‐level understanding of the effects of atmospheric‐pressure plasma on biological samples requires knowledge of the effects on proteins. Superoxide dismutases, which detoxify superoxide under oxidative stress conditions, play a key role in bacterial plasma resistance. Investigation of the impact of dielectric barrier discharge (DBD) treatment on purified superoxide dismutases SodA and SodB of Escherichia coli showed that DBD treatment caused a rapid protein degradation, with only 8% of protein remaining after 10 min. The affinity of SodA for the metal cofactor Mn2+ was reduced. Mass spectrometry, in conjunction with coupled‐cluster calculations, revealed that modifications of amino acid residues in the active site can explain the decreased metal affinity and a distortion of the coordination geometry responsible for the activity loss.
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|Plasma Source Specification|
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V(RMS) = 13.5 kV, trigger frequency = 300 Hz, diameter=20 mm
English (United States)
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Aqueous sample of 40 μl on stainless steel support placed on grounded support. Distance between sample and DBD was 1 mm.
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room temperature. no further control.
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Bandow, Julia E.
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purified superoxide dismutase. Escherichia coli BW25113, either ∆sodA, ∆sodB, ∆sodC, or ∆sodA∆sodB, taken from KEIO collection. 40 μl sample
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Data and Resources
- 01a SOD capacity of E.colicsv
One hundred micrograms of soluble protein extract of exponentially growing...
- 01b Bacterial growth with paraquatcsv
Paraquat sensitivity of SOD‐deletion strains was determined in growth...
- 01c Bacterial plasma sensitivitycsv
Plasma sensitivity of SOD‐deletion strains was determined in survival assays...
- 02b Residual protein activity after plasma treatmentcsv
The activity of residual SodA and SodB (relative specific activity) was...
- 02c Protein carbonylation after plasma treatmentcsv
2,4‐dinitrophenylhydrazine (DNPH), which reacts with carbonyl groups, was...
- 03 Estimation of plasma-generated peroxynitritecsv
A maximal estimate of peroxynitrite in plasma‐ treated buffer was calculated...
- 05a Raw tryptophan fluorescence of SodA for Mn-reconstitutioncsv
After removal of the manganese cofactor from untreated or plasma‐treated...
- S2a SOD-mimicking activity of plasma- treated buffercsv
The buffer (potassium phosphate, 100 mM, pH 7.5) was treated with the DBD...
- S2b SOD-mimicking activity of ROS in the enzyme assaycsv
Concentration-dependent activity of different long-living reactive species...
- S2c generation of Hydrogen peroxide by plasmacsv
Generation of hydrogen peroxide in buffer treated with DBD plasma as a...
- S2d Influence of catalase KatE on the activity of plasma-treated buffercsv
SOD-mimicking activity of plasma-treated buffer (10 min plasma treatment)...
- S3 Absorption spectra of NBT and NADH with or without plasma-treated buffer (PTB)csv
Absorption spectra of SOD assay solutions after 10 min pre-incubation and...
- 02a Protein concentration after plasma treatmentcsv
Protein concentration after plasma treatment was determined by the Bradford...
- S4a Influence of manganese ions on SOD activity assaycsv
Manganese salts (100 μM), untreated SodA, or plasma-treated SodA (10 min)...
- S4b Influence of iron ions on the SOD activity assaycsv
To determine the influence of free iron ions on the SOD activity assay, the...
- S5 CD spectroscopy of SodAcsv
CD spectroscopy of SodA after different durations of plasma treatment. CD...