Kinetics and mechanism of the chemiluminescence associated with the free radical-mediated oxidation of amino acids

Aspée, Alexis; Lissi, E. A.

doi:10.1002/1522-7243(200009/10)15:5<273::aid-bio591>3.0.co;2-m

Cited by 39 publications

(13 citation statements)

References 39 publications

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“…Chemiluminescence spectra, associated with lipid peroxidation, were found to emit in the range l max = 450-550 nm (7)(8)(9)(10). In a protein model, during amino acid oxidation, spectral emission was observed at 425 nm and 490 nm (11,12). Total photon emission from triplet carbonyls of other origins usually takes place above the 400-550 nm range.…”

Section: Rc--crmentioning

confidence: 99%

Modifications and oxidation of lipids and proteins in human serum detected by thermochemiluminescence

Shnizer¹,

Kagan

Lanir

et al. 2003

Luminescence

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Detection of electronically excited species (EES) in body fluids may constitute an important diagnostic tool in various pathologies. Examples of such products are triplet excited carbonyls (TEC), which can be a source for photon emission in the 400-550 nm range. The aim of the present study was to determine the actual contribution of lipid and protein components (protein carbonyls) to photon emission generated by thermochemiluminescence (TCL) during the heating of biological fluids. In this study, a new TCL Photometer device, designed by Lumitest Ltd, Israel, was used. Samples were heated to a constant temperature of 80 +/- 0.5 degrees C for 280 s and photon emission was measured at several time points. In order to compare the results of TCL measurements to conventional methods of detecting lipid and protein oxidation, each examined sample was also heated in a waterbath at 80 degrees C for 10-280 s. Lipid and protein oxidation were subsequently measured using conventional methods. The TCL of four polyunsaturated fatty acids (PUFA) with three to six double bonds was measured. The elevation of the PUFA TCL amplitude correlated with the increase in the number of double bonds of PUFA. A correlation between the increase in TCL intensity and protein carbonyl generation in bovine serum albumin (BSA) was also observed. In the venous blood serum, our study showed that an increase of TCL intensity during heating reflected the cleavage of TEC of lipid origin. Our study suggests that biological molecules such as proteins, lipids and other molecules, which may become unstable during heating, are capable of generating EES. We demonstrated that a TCL curve can be used as a kinetic model for measuring oxidative processes, which reflects modifications of different molecules involved in the oxidative stress phenomena.

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Section: Rc--crmentioning

confidence: 99%

Modifications and oxidation of lipids and proteins in human serum detected by thermochemiluminescence

Shnizer¹,

Kagan

Lanir

et al. 2003

Luminescence

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“…The steady increase in chemiluminescence is compatible with that expected if the emission arises from the decomposition of an oxidation product. 19,26,29 Furthermore, it is interesting to note that this emission is higher than that observed in the oxidation of histidine (Table 1), indicating that the conjugated double bond in urocanic acid contributes to the formation of chemiluminescence precursors. In order to have some insight on the mechanism of the chemiluminescence and the characteristics of its precursor, we added Ebselen (a compound with peroxidase-like activity) and Trolox (an efficient free radical scavenger) after 270 min incubation.…”

Section: Consumption Of Urocanic Acid Mediated By Peroxyl Radicalsmentioning

confidence: 83%

“…The chemiluminescence quenching by Ebselen would suggest that the emission precursor is a peroxide-like compound, while the almost total quenching elicited by Trolox addition would indicate that the chemiluminescence process is promoted by free radicals. 19,[26][27][28] It is interesting to note that, as in more complex systems, 29 chemiluminescence is strongly enhanced when the temperature increases. Typical data obtained when the sample preincubated at 37°C is introduced into the scintillation counter (kept at 23°C) are shown in Figure 3B.…”

Section: Consumption Of Urocanic Acid Mediated By Peroxyl Radicalsmentioning

confidence: 99%

“…All these results suggest that, following the incubation of trans-urocanic acid with the peroxyl radical source, products are formed (most probably peroxy-like) whose thermal decomposition leads to excited carbonyls. In this regard, trans-urocanic acid behaves as other biomolecules 19 or complex systems 29 whose oxidation leads to ultra-weak chemiluminescence. It is interesting to point out that UV-A irradiation of the skin generates a weak chemiluminescence 30 that, at least partially, could be due to trans-urocanic acid oxidation.…”

Section: Consumption Of Urocanic Acid Mediated By Peroxyl Radicalsmentioning

confidence: 99%

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Interaction and reactivity of urocanic acid towards peroxyl radicals

et al. 2005

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The capacity of urocanic acid to interact with peroxyl radicals has been evaluated in several systems: oxidation in the presence of a free radical source (2,2'-azobis(2-amidinopropane; AAPH), protection of phycocyanin bleaching elicited by peroxyl radicals, and Cu(II)- and AAPH-promoted LDL oxidation. The results indicate that both isomers (cis and trans) are mild peroxyl radical scavengers. For example, trans-urocanic acid is nearly 400 times less efficient than Trolox in the protection of the peroxyl radical promoted bleaching of phycocyanin. Regarding the removal of urocanic acid by peroxyl radicals, nearly 100 muM trans-urocanic acid is required to trap half of the produced radicals under the employed conditions (10 mM AAPH, 37 degrees C). Competitive experiments show that the cis-isomer traps peroxyl radicals 30% less efficiently than the trans-isomer. Given the high concentrations that trans-urocanic acid reaches in skin, its capacity to trap peroxyl radicals could contribute to the protection of the tissue towards ROS-mediated processes. Furthermore, both isomers, and particularly the cis-isomer, protect LDL from Cu(II)-induced oxidation.

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“…The emission of chemical luminescence from proteins is an indication of the interaction between oxidation intermediates (or products) and free radicals (Aspée & Lissi, 2000). Chemical luminescence occurs when the reaction intermediates in the excited state transition to the ground state with the release of energy in the form of photons.…”

Section: Introductionmentioning

confidence: 99%

Chemically stimulated luminescence from food proteins

2018

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Background and objectives: Protein powders contain metastable radicals that are released upon hydration. The influence of protein source, free radical content, and hydration condition on luminescence was investigated. Findings: Hydration of rice, soy, pea, and egg albumin generated a burst of luminescence in the absence of added enhancers/stimulates. Rice proteins were generated from 3 to 10 times more luminescence than other protein samples. Hydrating proteins with 25 mM H 2 O 2 increased the luminescence intensities from all food proteins. Luminescence maximums occurred between 550-600 nm for rice protein, 500-600 nm for soy protein, and two peaks from egg albumin (500-550 nm and <450 nm). Carbon-centered metastable radicals were most abundant in rice protein which contained between 3.87 × 10 16 -53.44 × 10 16 spins per gram. Plotting intrinsic luminescence versus spins per gram (including all types of proteins examined) revealed an r-square of 0.771. Conclusions: Based on peak shape, g-value (2.0050 ± 0.0003) and power saturation (4-8 mW), metastable radicals in proteins were identified as carbon-centered. Both intrinsic and added sources of oxidative stimuli strongly correlate with the generation of chemically stimulated luminescence from hydrated proteins. Significance and novelty: These findings are the first to correlate the quantity of metastable radicals in rice proteins with intrinsic luminescence generated upon hydration and provide spectral characterization of luminescence from these proteins. K E Y W O R D Scarbon-centered metastable radicals, chemically stimulated luminescence, electron paramagnetic resonance spectroscopy, rice protein concentrates

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Kinetics and mechanism of the chemiluminescence associated with the free radical-mediated oxidation of amino acids

Cited by 39 publications

References 39 publications

Modifications and oxidation of lipids and proteins in human serum detected by thermochemiluminescence

Modifications and oxidation of lipids and proteins in human serum detected by thermochemiluminescence

Interaction and reactivity of urocanic acid towards peroxyl radicals

Chemically stimulated luminescence from food proteins

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