scholarly journals Radiation- and Photo-Induced Oxidation Pathways of Methionine in Model Peptide Backbone under Anoxic Conditions

2021 ◽  
Vol 22 (9) ◽  
pp. 4773
Author(s):  
Tomasz Pędzinski ◽  
Katarzyna Grzyb ◽  
Konrad Skotnicki ◽  
Piotr Filipiak ◽  
Krzysztof Bobrowski ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Pulse Radiolysis ◽  
Oxygen Species ◽  
Transient Species ◽  
Model Peptide ◽  
Peptide Backbone ◽  
Anoxic Conditions ◽  
Product Identification ◽  
Stable Product ◽  
Methionine Residues

Within the reactive oxygen species (ROS) generated by cellular metabolisms, hydroxyl radicals (HO•) play an important role, being the most aggressive towards biomolecules. The reactions of HO• with methionine residues (Met) in peptides and proteins have been intensively studied, but some fundamental aspects remain unsolved. In the present study we examined the biomimetic model made of Ac-Met-OMe, as the simplest model peptide backbone, and of HO• generated by ionizing radiation in aqueous solutions under anoxic conditions. We performed the identification and quantification of transient species by pulse radiolysis and of final products by LC-MS and high-resolution MS/MS after γ-radiolysis. By parallel photochemical experiments, using 3-carboxybenzophenone (CB) triplet with the model peptide, we compared the outcomes in terms of short-lived intermediates and stable product identification. The result is a detailed mechanistic scheme of Met oxidation by HO•, and by CB triplets allowed for assigning transient species to the pathways of products formation.

scholarly journals Sulfide (Na2S) and Polysulfide (Na2S2) Interacting with Doxycycline Produce/Scavenge Superoxide and Hydroxyl Radicals and Induce/Inhibit DNA Cleavage

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1148 ◽  
Author(s):  
Anton Misak ◽  
Lucia Kurakova ◽  
Eduard Goffa ◽  
Vlasta Brezova ◽  
Marian Grman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydroxyl Radicals ◽  
Plasmid Dna ◽  
Dna Cleavage ◽  
Biological Effects ◽  
Antibacterial Treatment ◽  
Ros Production ◽  
Biological Processes ◽  
Oxygen Species ◽  
Cleavage Assay

Doxycycline (DOXY) is an antibiotic routinely prescribed in human and veterinary medicine for antibacterial treatment, but it has also numerous side effects that include oxidative stress, inflammation, cancer or hypoxia-induced injury. Endogenously produced hydrogen sulfide (H2S) and polysulfides affect similar biological processes, in which reactive oxygen species (ROS) play a role. Herein, we have studied the interaction of DOXY with H2S (Na2S) or polysulfides (Na2S2, Na2S3 and Na2S4) to gain insights into the biological effects of intermediates/products that they generate. To achieve this, UV-VIS, EPR spectroscopy and plasmid DNA (pDNA) cleavage assay were employed. Na2S or Na2S2 in a mixture with DOXY, depending on ratio, concentration and time, displayed bell-shape kinetics in terms of producing/scavenging superoxide and hydroxyl radicals and decomposing hydrogen peroxide. In contrast, the effects of individual compounds (except for Na2S2) were hardly observable. In addition, DOXY, as well as oxytetracycline and tetracycline, interacting with Na2S or other studied polysulfides reduced the •cPTIO radical. Tetracyclines induced pDNA cleavage in the presence of Na2S. Interestingly, they inhibited pDNA cleavage induced by other polysulfides. In conclusion, sulfide and polysulfides interacting with tetracyclines produce/scavenge free radicals, indicating a consequence for free radical biology under conditions of ROS production and tetracyclines administration.

scholarly journals Biological Activity of Dolichandrone Serrulata Flowers and Their Active Components

2015 ◽  
Vol 10 (8) ◽  
pp. 1934578X1501000
Author(s):  
Phanida Phanthong ◽  
Noppawan Phumala Morales ◽  
Sirirat Chancharunee ◽  
Supachoke Mangmool ◽  
Natthinee Anantachoke ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Reactive Oxygen Species Production ◽  
Protocatechuic Acid ◽  
Methanolic Extract ◽  
Oxygen Species ◽  
Active Components ◽  
Hek 293 ◽  
Biological Studies ◽  
Weak Activity ◽  
Species Production

Dolichandrone serrulata (DC.) Seem flowers are widely used as vegetables in northern and eastern Thailand. Biological studies of the methanolic extract of these flowers have shown promising antioxidant activity. Biological-guided separation of D. serrulata flowers yielded six compounds, identified as hallerone, protocatechuic acid, rengyolone, cleroindicin B, ixoside, and isomaltose. This is the first report on hallerone, protocatechuic acid, rengyolone, cleroindicin B, and isomaltose in D. serrulata. Protocatechuic acid was the most potent scavenger of 2,2-diphenyl-l-picrylhydrazyl and hydroxyl radicals with IC50 values of 25.6 ± 0.6 and 29.6 ± 0.4 μM, respectively. Hallerone and rengyolone showed moderate scavenging action on superoxide radicals and inhibited H2O2 induced reactive oxygen species production in HEK-293 cell. In addition, the other isolated compounds showed weak activity.

Deamination of β-alanine induced by hydroxyl radicals and monovalent copper ions. A pulse radiolysis study

1992 ◽  
Vol 192 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Sara Goldstein ◽  
Gidon Czapski ◽  
Haim Cohen ◽  
Dan Meyerstein
Keyword(s):  
Hydroxyl Radicals ◽  
Pulse Radiolysis ◽  
Copper Ions

scholarly journals Role of mitochondrial superoxide dismutase in contraction-induced generation of reactive oxygen species in skeletal muscle extracellular space

2004 ◽  
Vol 286 (5) ◽  
pp. C1152-C1158 ◽  
Author(s):  
A. McArdle ◽  
J. van der Meulen ◽  
G. L. Close ◽  
D. Pattwell ◽  
H. Van Remmen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Extracellular Space ◽  
Superoxide Anion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Superoxide Anions ◽  
Wild Type ◽  
Mnsod Activity

Contractions of skeletal muscles produce increases in concentrations of superoxide anions and activity of hydroxyl radicals in the extracellular space. The sources of these reactive oxygen species are not clear. We tested the hypothesis that, after a demanding isometric contraction protocol, the major source of superoxide and hydroxyl radical activity in the extracellular space of muscles is mitochondrial generation of superoxide anions and that, with a reduction in MnSOD activity, concentration of superoxide anions in the extracellular space is unchanged but concentration of hydroxyl radicals is decreased. For gastrocnemius muscles from adult (6–8 mo old) wild-type ( Sod2+/+) mice and knockout mice heterozygous for the MnSOD gene ( Sod2+/-), concentrations of superoxide anions and hydroxyl radical activity were measured in the extracellular space by microdialysis. A 15-min protocol of 180 isometric contractions induced a rapid, equivalent increase in reduction of cytochrome c as an index of superoxide anion concentrations in the extracellular space of Sod2+/+ and Sod2+/- mice, whereas hydroxyl radical activity measured by formation of 2,3-dihydroxybenzoate from salicylate increased only in the extracellular space of muscles of Sod2+/+ mice. The lack of a difference in increase in superoxide anion concentration in the extracellular space of Sod2+/+ and Sod2+/- mice after the contraction protocol supported the hypothesis that superoxide anions were not directly derived from mitochondria. In contrast, the data obtained suggest that the increase in hydroxyl radical concentration in the extracellular space of muscles from wild-type mice after the contraction protocol most likely results from degradation of hydrogen peroxide generated by MnSOD activity.

scholarly journals Involvement of the MetO/Msr System in Two Acer Species That Display Contrasting Characteristics during Germination

2020 ◽  
Vol 21 (23) ◽  
pp. 9197
Author(s):  
Natalia Wojciechowska ◽  
Shirin Alipour ◽  
Ewelina Stolarska ◽  
Karolina Bilska ◽  
Pascal Rey ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Superoxide Anion ◽  
Redox Homeostasis ◽  
Methionine Sulfoxide ◽  
Redox System ◽  
Oxygen Species ◽  
Embryonic Axes ◽  
Methionine Sulfoxide Reductases ◽  
Germination Process ◽  
Norway Maple

The levels of methionine sulfoxide (MetO) and the abundances of methionine sulfoxide reductases (Msrs) were reported as important for the desiccation tolerance of Acer seeds. To determine whether the MetO/Msrs system is related to reactive oxygen species (ROS) and involved in the regulation of germination in orthodox and recalcitrant seeds, Norway maple and sycamore were investigated. Changes in water content, MetO content, the abundance of MsrB1 and MsrB2 in relation to ROS content and the activity of reductases depending on nicotinamide adenine dinucleotides were monitored. Acer seeds differed in germination speed—substantially higher in sycamore—hydration dynamics, levels of hydrogen peroxide, superoxide anion radicals (O2•−) and hydroxyl radicals (•OH), which exhibited peaks at different stages of germination. The MetO level dynamically changed, particularly in sycamore embryonic axes, where it was positively correlated with the levels of O2•− and the abundance of MsrB1 and negatively with the levels of •OH and the abundance of MsrB2. The MsrB2 abundance increased upon sycamore germination; in contrast, it markedly decreased in Norway maple. We propose that the ROS–MetO–Msr redox system, allowing balanced Met redox homeostasis, participates in the germination process in sycamore, which is characterized by a much higher speed compared to Norway maple.

scholarly journals Profiling the oxidative activation of DMSO-F6 by pulse radiolysis and translational potential for radical C–H trifluoromethylation

2019 ◽  
Vol 17 (45) ◽  
pp. 9734-9742 ◽  
Author(s):  
Nico Santschi ◽  
Benson J. Jelier ◽  
Samuel Stähelin ◽  
Thomas Nauser
Keyword(s):  
Dimethyl Sulfoxide ◽  
Hydroxyl Radicals ◽  
Pulse Radiolysis ◽  
Oxidative Activation

The improved synthesis of perfluorinated dimethyl sulfoxide, DMSO-F6, and its activation with hydroxyl radicals to afford trifluoromethyl radicals is presented.

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