Effect of Local Environment and Protein on the Mechanism of Action of Superoxide Dismutase

Enzyme ◽  
1986 ◽  
Vol 36 (1-2) ◽  
pp. 32-43 ◽  
Author(s):  
Roman Osman
Keyword(s):  
Superoxide Dismutase ◽  
Mechanism Of Action ◽  
Local Environment

scholarly journals The involvement of the bridging imidazolate in the catalytic mechanism of action of bovine superoxide dismutase

1977 ◽  
Vol 167 (1) ◽  
pp. 271-274 ◽  
Author(s):  
M E McAdam ◽  
E M Feilden ◽  
F Lavelle ◽  
L Calabrese ◽  
D Cocco ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Nitrogen Atom ◽  
Mechanism Of Action ◽  
Pulse Radiolysis ◽  
Catalytic Mechanism ◽  
Catalytic Reduction ◽  
Rapid Change ◽  
Proton Donor ◽  
Spectral Changes ◽  
Rapid Protonation

The pulse-radiolysis method has been used to study the catalytic mechanism of O2 leads to dismutation by the Co(II)-substituted bovine erythrocuprein (superoxide dismutase, EC 1.15.1.1). Catalysis is accompanied by spectral changes that may be interpreted in terms of rapid protonation and deprotonation of the Cu-facing nitrogen atom of the imidazolate that bridges the Cu(II) and the Co(II) [or Zn(II)] in the oxidized enzyme. This rapid change permits the possibility that the imidazole is a proton donor in the catalytic reduction of O2 leads to.

scholarly journals Comparative Transcriptome Analysis Reveals the Mechanism Related to Fluazinam Stress of Panonychus citri (Acarina: Tetranychidae)

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 730
Author(s):  
Yi Shang ◽  
Yanbo Wang ◽  
Jianyu Deng ◽  
Xunyue Liu ◽  
Yihao Fang ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Mechanism Of Action ◽  
Good Control ◽  
Glutathione S Transferase ◽  
Control Effect ◽  
Panonychus Citri ◽  
Transcriptomic Sequencing ◽  
Cytochrome P450 Genes ◽  
Differential Expression Genes ◽  
And Control

The use of a large number of chemical acaricides to control these pest mites has led to an increasing problem of pesticide resistance, which has always been the difficulty in integrated pest management (IPM). Fluazinam has a good control effect on Panonychus citri, the serious pest on citrus; however, we only know the mechanism of action of fluazinam as a fungicide and its mechanism of action on mites remains unclear. Through analysis using Illumina high-throughput transcriptomic sequencing and differential expression genes in P. citri treated with fluazinam, 59 cytochrome P450 genes, 23 glutathione s-transferase genes, five carboxylate esterase genes, 11 superoxide dismutase genes and 15 catalase genes were identified. The Gene Ontology enrichment and the enrichment of KEGG results showed that the treatment were enrichment for redox enzyme pathways. Evaluating the efficacy of fluazinam, and analyzing the transcriptome data of P. citri under fluazinam stress, potentially provide a new agent for prevention and control of P. citri, and also preliminary research results for exploring the mechanism of action of fluazinam on P. citri. Given the up-regulated expression levels of genes for Mn-superoxide dismutase and catalase, we speculate that they play an important role in fluazinam-stress action on P. citri.

scholarly journals Antioxidant and antiaggregant effects of covalent bienzyme superoxide dismutase - chondroitin sulfate - catalase conjugate in platelet interactions

2012 ◽  
Vol 58 (3) ◽  
pp. 300-309
Author(s):  
A.V. Vavaev ◽  
L.I. Buryachkovskaya ◽  
E.G. Tischenko ◽  
I.A. Uchitel ◽  
A.V. Maksimenko
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Superoxide Dismutase ◽  
Platelet Aggregation ◽  
Chondroitin Sulfate ◽  
Mechanism Of Action ◽  
Inhibitory Action ◽  
Induced Aggregation ◽  
Dose Dependent ◽  
Aggregation Of Platelets

A covalent bienzyme superoxide dismutase-chondroitin sulfate-catalase conjugate (SOD-CHS-CAT) demonstrated the dose-dependent inhibitory action on induced aggregation of platelets in the presence of hydrogen peroxide. Antioxidant activity of SOD-CHS-CAT appeared at much lower doses than for other CAT derivatives. We detected the antiaggregation effect of SOD-CHS-CAT for platelet aggregation induced by ADP, serotonin, TRAP (with their different mechanism of action). Novel properties of SOD-CHS-CAT confirmed with its action agains spread-eagle platelets on glass surface. The new characteristics of SOD-CHS-CAT conjugate underline the prospects of its biopharmaceutical development for antioxidant therapy.

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

1969 ◽  
Vol 27 ◽  
pp. 82-83
Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Local Environment ◽  
Chamber Pressure ◽  
Objective Lens ◽  
Ion Pump ◽  
Quantitative Studies ◽  
Precise Knowledge ◽  
Differential Pumping ◽  
And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

Electron energy-loss near-edge structure in silicate minerals

1992 ◽  
Vol 50 (2) ◽  
pp. 1258-1259
Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson
Keyword(s):  
Solid State ◽  
Energy Loss ◽  
Electron Energy ◽  
State Energy ◽  
Local Environment ◽  
Edge Structure ◽  
Silicate Minerals ◽  
Two Samples ◽  
Electron Energy Loss ◽  
Careful Processing

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.

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