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1.
Cellular redox state is regulated by numerous components. The thiol-disulfide compound, glutathione, is considered to be one of the most significant, owing to its antioxidant power and potential influence over protein structure and function. While signaling roles for glutathione in plants have been suggested for several years, hard proof is scarce. Recently, through an approach based on genetic manipulation of glutathione in an oxidative stress background, we reported evidence that glutathione status is important to allow intracellular oxidation to activate pathogenesis-related phytohormone signaling pathways. This effect does not seem to be caused by changes in glutathione antioxidant capacity, and appears to be distinct to regulation through known players in pathogenesis responses, such as NPR1. Our data therefore suggest that new glutathione-dependent components that link oxidative stress to response outputs await discovery. 相似文献
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Touseef Amna M. Shamshi Hassan Faheem A. Sheikh Hak Kyo Lee Kang-Seok Seo Duhak Yoon I. H. Hwang 《Applied microbiology and biotechnology》2013,97(4):1725-1734
Zinc oxide (ZnO) nanostructures have been commonly studied for electronic purposes due to their unique piezoelectric and catalytic properties; however, recently, they have been also exploited for biomedical applications. The purpose of this study was to fabricate ZnO-doped poly(urethane) (PU) nanocomposite via one-step electrospinning technique. The utilized nanocomposite was prepared by using colloidal gel composed of ZnO and PU, and the obtained mats were vacuum dried at 60 °C overnight. The physicochemical characterization of as-spun composite nanofibers was carried out by X-ray diffraction pattern, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron probe microanalysis, and transmission electron microscopy, whereas the thermal behavior was analyzed by thermogravimetric analysis. The viability, attachment, and proliferation of NIH 3T3 mouse fibroblast cells on the ZnO/PU composite nanofibers were analyzed by in vitro cell compatibility test. The morphological features of the cells attached on nanofibers were examined by Bio-SEM. We conclude that the electrospun nanofibrous scaffolds with unique spider nets had good biocompatibility. Cytotoxicity experiments indicated that the mouse fibroblasts could attach to the nanocomposite after being cultured. Thus, the current work demonstrates that the as-synthesized ZnO/PU hybrid nanofibers represent a promising biomaterial to be exploited for various tissue engineering applications. 相似文献
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Samia E. Omer Tawasol M. Ibrahim Omer A. Krar Amna M. Ali Alaa A. Makki Walaa Ibraheem Abdulrahim A. Alzain 《Biochemistry and Biophysics Reports》2022
The current novel corona virus illness (COVID-19) is a developing viral disease that was discovered in 2019. There is currently no viable therapeutic strategy for this illness management. Because traditional medication development and discovery has lagged behind the threat of emerging and re-emerging illnesses like Ebola, MERS-CoV, and, more recently, SARS-CoV-2. Drug developers began to consider drug repurposing (or repositioning) as a viable option to the more traditional drug development method. The goal of drug repurposing is to uncover new uses for an approved or investigational medicine that aren't related to its original use. The main benefits of this strategy are that there is less developmental risk and that it takes less time because the safety and pharmacologic requirements are met. The main protease (Mpro) of corona viruses is one of the well-studied and appealing therapeutic targets. As a result, the current research examines the molecular docking of Mpro (PDB ID: 5R81) conjugated repurposed drugs. 12,432 approved drugs were collected from ChEMBL and drugbank libraries, and docked separately into the receptor grid created on 5R81, using the three phases of molecular docking including high throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP). Based on docking scores and MM-GBSA binding free energy calculation, top three drugs (kanamycin, sulfinalol and carvedilol) were chosen for further analyses for molecular dynamic simulations. 相似文献
5.
Margison GP Butt A Pearson SJ Wharton S Watson AJ Marriott A Caetano CM Hollins JJ Rukazenkova N Begum G Santibáñez-Koref MF 《DNA Repair》2007,6(8):1222-1228
Recent in silico analysis has revealed the presence of a group of proteins in pro and lower eukaryotes, but not in Man, that show extensive amino acid sequence similarity to known O(6)-alkylguanine-DNA alkyltransferases, but where the cysteine at the putative active site is replaced by another residue, usually tryptophan. Here we review recent work on these proteins, which we designate as alkyltransferase-like (ATL) proteins, and consider their mechanism of action and role in protecting the host organisms against the biological effects of O(6)-alkylating agents, and their evolution. ATL proteins from Escherichia coli (eAtl, transcribed from the ybaz open reading frame) and Schizosaccharomyces pombe (Atl1) are able to bind to a range of O(6)-alkylguanine residues in DNA and to reversibly inhibit the action of the human alkyltransferase (MGMT) upon these substrates. Isolated proteins were not able to remove the methyl group in O(6)-methylguanine-containing DNA or oligonucleotides, neither did they display glycosylase or endonuclease activity. S. pombe does not contain a functional alkyltransferase and atl1 inactivation sensitises this organism to a variety of alkylating agents, suggesting that Atl1 acts by binding to O(6)-alkylguanine lesions and signalling them for processing by other DNA repair pathways. Currently we cannot exclude the possibility that ATL proteins arose through independent mutation of the alkyltransferase gene in different organisms. However, analyses of the proteins from E. coli and S. pombe, are consistent with a common function. 相似文献
6.
Three genes encode catalase in Arabidopsis. Although the role of CAT2 in photorespiration is well established, the importance of the different catalases in other processes is less clear. Analysis of cat1, cat2, cat3, cat1 cat2, and cat2 cat3 T‐DNA mutants revealed that cat2 had the largest effect on activity in both roots and leaves. Root growth was inhibited in all cat2‐containing lines, but this inhibition was prevented by growing plants at high CO2, suggesting that it is mainly an indirect effect of stress at the leaf level. Analysis of double mutants suggested some overlap between CAT2 and CAT3 functions in leaves and CAT1 and CAT2 in seeds. When plants had been grown to a similar developmental stage in short days or long days, equal‐time exposure to oxidative stress caused by genetic or pharmacological inhibition of catalase produced a much stronger induction of H2O2 marker genes in short day plants. Together, our data (a) underline the importance of CAT2 in basal H2O2 processing in Arabidopsis; (b) suggest that CAT1 and CAT3 are mainly “backup” or stress‐specific enzymes; and (c) establish that day length‐dependent responses to catalase deficiency are independent of the duration of oxidative stress. 相似文献
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Taha Ramadan Suzan A. Sayed Amna K. A. Abd-Elaal Ahmed Amro 《Physiology and Molecular Biology of Plants》2022,28(2):391
Nanotechnology has become one of the several approaches attempting to ameliorate the severe effect of drought on plant''s production and to increase the plants tolerance against water deficit for the water economy. In this research, the effect of foliar application of TiO2, nanoparticles or ordinary TiO2, on Helianthus annuus subjected to different levels of water deficit was studied. Cell membrane injury increased by increasing the level of water deficit and TiO2 concentration, and both types of TiO2 affected the leaves in analogous manner. Ord-TiO2 increased H2O2 generation by 67–240% and lipid peroxidation by 4–67% in leaves. These increases were more than that induced by Nano-TiO2 and the effect was concentration dependent. Proline significantly increased in leaves by water deficit stress, reaching at 25% field capacity (FC) to more than fivefold compared to that in plants grown on full FC. Spraying plants with water significantly decreased the activities of enzymes in the water deficit stressed roots. The water deficit stress exerted the highest magnitude of effect on the changes of cell membrane injury, MDA, proline content, and activities of CAT and GPX. Nano-TiO2 was having the highest effect on contents of H2O2 and GPX activity. In roots, the level of water deficit causes highest effect on enzyme activities, but TiO2 influenced more on the changes of MDA and H2O2 contents. GPX activity increased by 283% in leaves of plants treated with 50 and 150 ppm Nano-TiO2, while increased by 170% in those treated with Ord-TiO2, but APX and CAT activities increased by 17–197%, in average, with Ord-TiO2. This study concluded that Nano-TiO2 didn’t ameliorate the effects of drought stress on H. annuus but additively increased the stress, so its use in nano-phytotechnology mustn’t be expanded without extensive studies.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-022-01153-z. 相似文献
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We have developed a system for rapid and reliable assessment of gene essentiality in Haemophilus influenzae Rd strain KW20. We constructed two "suicide" complementation vectors (pASK5 and pASK6) containing 5' and 3' regions of the nonessential ompP1 gene flanking a multiple cloning site and a selectable marker (a chloramphenicol resistance gene or a tetracycline resistance cassette). Transformation of H. influenzae with the complementation constructs directs chromosomal integration of a gene of interest into the ompP1 locus, where the strong, constitutive ompP1 promoter drives its expression. This single-copy, chromosome-based complementation system is useful for confirming the essentiality of disrupted genes of interest. It allows genetic analysis in a background free of interference from any upstream or downstream genetic elements and enables conclusive assignment of essentiality. We validated this system by using the riboflavin synthase gene (ribC), a component of the riboflavin biosynthetic pathway. Our results confirmed the essentiality of ribC for survival of H. influenzae Rd strain KW20 and demonstrated that a complementing copy of ribC placed under control of the ompP1 promoter reverses the lethal phenotype of a strain with ribC deleted. 相似文献
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Amna Al-Otaiba Annie John Thekra Al-Belooshi Haider Raza 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2010,180(8):1121-1132
We have previously reported the occurrence of multiple forms of drug-metabolizing enzymes in camel tissues. Here, we investigate
glutathione (GSH)-dependent redox homeostasis, reactive oxygen species (ROS) production and mitochondrial respiratory functions
in camel tissues and compare them with imported domestic goats and laboratory rats and mice. Cytochrome P450 2E1 (CYP 2E1)
and GSH-metabolizing enzymes were differentially expressed in the liver and kidney of these animals. Camel liver has significantly
lower GSH pool than that in goats, rats and mice. Mitochondria isolated from the tissues of these animals showed a comparable
ability to metabolize specific substrates for respiratory enzyme complexes I, II/III and IV. These complexes were metabolically
more active in the kidney than in the liver of all the species. Furthermore, the activity of complex IV in camel tissues was
significantly lower than in other species. On the other hand, complex II/III activity in camel kidney was higher compared
to the other species. In addition, as expected, we observed that inhibitors of these enzyme complexes augment the production
of mitochondrial ROS in camel and goat tissues. These results help to better understand the metabolic ability and adaptation
in desert camels in comparison with domestic goats and laboratory rats and mice since they are exposed to different environmental
and dietary conditions. Our study may also have implications in the pharmacology and toxicology of drugs and pollutants in
these species. 相似文献
10.
Peroxisomal Hydrogen Peroxide Is Coupled to Biotic Defense Responses by ISOCHORISMATE SYNTHASE1 in a Daylength-Related Manner 总被引:1,自引:0,他引:1