Free radicals in chemistry and biology

Lazár, M.; Rychlý, Jozef; Klimo, Viliam; Pelikán, P.; Valko, L.

doi:10.1016/0891-5849(91)90175-3

Cited by 35 publications

(67 citation statements)

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“…Free radical production, detected by spin-trapping and EPR, has been reported for Aß(l-40), Aß (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35), Aß(35-25) (reverse sequence), and Aß(25-35) (scrambled sequence) [2,3,28]. In addition, human amylin and ß2-microglobulin and other amyloidogenic proteins also damage cells by a free radical-dependent, fibril-dependent mechanism [22].…”

Section: Fibrilogenesis Free Radical Production and Neurotoxicitymentioning

confidence: 99%

“…The maximum extent of spin trapped radical from Aß(25-35) was reported to be one radical per 25 polypeptides [5], which suggested that the mechanism of radical production was not coupled to fibrilogenesis in a strictly stoichiometric mechanism. Similarly, the extent of peroxideequivalent production by Aß (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) was recently reported to be 10 NM per mg/ml peptide incubate [3], or roughly one per 70 Aß (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) monomers. Given the low stoichiometry, it is here proposed that abnormal association during fibrilogenesis better accounts for the observed level of free radical and peroxide production than does a model based upon the chemistry of an homogenous fibril structure.…”

Section: Fibrilogenesis Free Radical Production and Neurotoxicitymentioning

confidence: 99%

“…Studies of the biological activity of Aß suggest it may potentiate neurotoxicity, or be directly neurotoxic [1]. Recent evidence has shown that synthetic Aß and certain truncated Aß peptides, particularly Aß (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) 1 , generate peptidyl free radicals and reactive oxygen species (ROS) in the presence of oxygen and apparent absence of metal ions or other free radical initiators [2,3]. A close correlation has been demonstrated between free radical production by these peptides and the ability to promote oxidative reactions associated with AD etiology, including cultured neuronal cell lipid peroxidation [4], inhibition of glutamine synthetase activity [5], inhibition of creatine kinase activity [5], and inhibition of ion-motive ATPases [6].…”

Section: Introductionmentioning

confidence: 99%

“…E-mail: ckay@coml.med.usf.edu Aß toxicity is closely correlated with the aggregation state of the polypeptide. Freshly solubilized Aß may only exhibit neurotoxicity after several days of preincubation [9,10], while shorter peptides such as Aß (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) aggregate rapidly with concomitant free radical production and neurotoxicity [5,7,9]. Agents such as Congo red [11] and related sulfonated dyes [12] attenuate neurotoxicity and may inhibit fibrilogenesis.…”

Section: Introductionmentioning

confidence: 99%

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Mechanochemical mechanism for peptidyl free radical generation by amyloid fibrils

Kay

1997

FEBS Letters

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ß-Amyloid peptides (Aß) form the core of Alzheimer's disease (AD) senile plaques, and are implicated in AD neurotoxicity. Aß and some derivatives generate free radicals upon fibrilogenesis. A mechanism for free radical generation is proposed, based upon fibril cross ß-sheet structure: (1) During fibrilogenesis there is a small probability of mispacking of Aß monomers, resulting in abnormal fibril packing. (2) Continued fibrilogenesis traps a packing defect within the ß-sheet. Surrounding ß-sheet resists distortion, and the abnormally packed polypeptide(s) is strained. (3) Thermal processes cause homolytic bond scission and radical production from strained polypeptide through mechanically activated thermal decomposition. (4) Reaction with oxygen produces peroxy radicals, prevents unproductive radical recombination, and promotes observed cross-linking, production of reactive oxygen species and peptide fragmentation. Adiabatic mapping suggested significant strain would be generated by ß-sheet misalignment. The mechanism relates the common structure of fibrils to radical production, and may be relevant to cytotoxicity in prion and other amyloidoses.

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Section: Fibrilogenesis Free Radical Production and Neurotoxicitymentioning

confidence: 99%

Section: Fibrilogenesis Free Radical Production and Neurotoxicitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mechanochemical mechanism for peptidyl free radical generation by amyloid fibrils

Kay

1997

FEBS Letters

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“…The results of earlier studies have established that AAPH leads to the formation of carboncentered radicals, which yield alklyperoxyl radicals and hydroperoxides that are capable of modifying lipid and DNA under aerobic conditions (13)(14)(15)(16). In order to study the effect of hSelM overexpression under high levels of free radicals, the concentration of total antioxidant and H 2 O 2 was determined in the serum of CMV/GFP-hSelM Tg and non-Tg rats after AAPH injection using an ELISA kit.…”

Section: Effect Of Selm Overexpression On the H 2 O 2 And Total Antiomentioning

confidence: 99%

Overexpression of human selenoprotein M differentially regulates the concentrations of antioxidants and H2O2, the activity of antioxidant enzymes, and the composition of white blood cells in a transgenic rat

Hwang¹,

Sin²,

Kim³

et al. 2008

Int J Mol Med

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Abstract. Selenoprotein is associated with a variety of serious diseases, including infectious diseases, neurodegenerative disorders, cancer and cardiovascular disease. The aim of this study was to produce a new transgenic (Tg) rat expressing human selenoprotein M (SelM) in order to examine the protective function of the antioxidant status in vivo. To achieve this, a new lineage of Tg rats was produced by the microinjection of pCMV/GFP-hSelM constructs into a fertilized rat egg. Several conclusions can be drawn based on the results of the present study. The human SelM gene was successfully expressed at both the transcription and protein levels in the CMV/GFP-hSelM Tg rats. This Tg rat showed a different enzyme activity for the antioxidant protein in the various tissues examined. In response to the 2,2'-azobiz(2-amidinopropane) dihydrochloride (AAPH) injection, the Tg rats showed a lower level of antioxidant and H 2 O 2 concentration as the activity of the antioxidant enzyme was maintained at a higher level in the Tg rats than in the non-Tg rats. Also, the neutrophil-to-lymphocyte ratio was significantly increased in this Tg rat, even though the level of corticosterone remained unchanged in both genotypes. Thus, the results of this study demonstrated that the CMV/GFP-hSelM Tg rat can serve as an animal model for the maintenance of a high level of antioxidant status and can be used to study the biological function of selenoprotein in infectious diseases, cardiovascular disease and cancer.

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Ambient Stable Zwitterionic Perylene Bisimide‐Centered Radical

2014

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The unexpected introduction of a cationic imidazolium substituent in the 2-position of a tetrachloro-substituted perylene-3,4:9,10-tetracarboxylic acid bisimide (PBI) by the reaction of PBI-Cl4 1 with the N-heterocyclic carbene 1,3-di-iso-propyl-imidazolin-2-ylidene ((i)Pr2Im 2) enables the isolation of an ambient stable zwitterionic radical. The remarkable stability of this unprecedented PBI-centered radical facilitates the complete characterization by several spectroscopic methods as well as single crystal structure analysis. Redox studies revealed that (i)Pr2Im-PBI-Cl4 4 can be transferred reversibly to the corresponding anion and cation, respectively, even on a preparative scale.

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Free radicals in chemistry and biology

Cited by 35 publications

References 0 publications

Mechanochemical mechanism for peptidyl free radical generation by amyloid fibrils

Mechanochemical mechanism for peptidyl free radical generation by amyloid fibrils

Overexpression of human selenoprotein M differentially regulates the concentrations of antioxidants and H2O2, the activity of antioxidant enzymes, and the composition of white blood cells in a transgenic rat

Ambient Stable Zwitterionic Perylene Bisimide‐Centered Radical

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