Formation of Carbonyls during Attack on Insulin by Submolar Amounts of Hypochlorite

Handelman, Garry J.; Nightingale, Zachary D; Dolnikowski, Gregory G.; Blumberg, Jeffrey B.

doi:10.1006/abio.1998.2592

Cited by 15 publications

(9 citation statements)

References 38 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2D and 2E) show a molecular mass of M r = 17131.6 and of 17131.2, respectively. This represents a mass increase of 179 Da over the native protein, which is consistent with 2,4-DNPH-reactive proteins that have undergone an oxidative deamination before derivatization with the 2,4-DNPH reagent (44, 45). Thus, the observation of these peaks provides the first solid evidence that the nitroxide + H 2 O 2 -modified Mb has undergone an oxidative deamination in which some amino groups were converted to free carbonyls.…”

Section: Resultssupporting

confidence: 72%

Spin Scavenging Analysis of Myoglobin Protein-Centered Radicals Using Stable Nitroxide Radicals: Characterization of Oxoammonium Cation-Induced Modifications

Lardinois

Maltby

Medzihradszky

et al. 2009

Chem. Res. Toxicol.

View full text Add to dashboard Cite

Spin scavenging combined with chromatographic and mass spectrometric procedures can, in principle, be employed to detect and identify protein-based radicals within complex biological matrices. This approach is based on the well-known ability of stable synthetic nitroxide radicals to scavenge carbon-centered radicals, forming stable diamagnetic addition products. Hence, characterization of these addition products would allow for the identification of specific free radicals. In the present work, we have explored the use of the stable nitroxide radical 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) in scavenging protein-based radicals generated in a horse heart metmyoglobin/hydrogen peroxide (metMb/H2O2) system. Inclusion of a substoichiometric amount of TEMPOL in the metMb/H2O2 system resulted in a complete loss of peroxyl and tyrosyl radical signals and effectively inhibited the formation of oxidatively-damaged heme species, as monitored by electron paramagnetic resonance and reverse-phase liquid chromatography. Scavenging of globin radicals by TEMPOL did not lead to the formation of stable diamagnetic addition adducts; in fact, reverse-phase liquid chromatographic studies and oxygen electrode measurements indicated that TEMPOL acts as a catalyst and is recycled in this system. The oxoammonium cation generated in the course of this reaction initiated secondary reactions resulting in the formation of a free carbonyl on the N-terminal Gly-residue of the protein. This oxidative deamination was confirmed through the combined use of reverse-phase liquid chromatographic purification, tandem MS experiments and chemical analysis (e.g. by use of 2,4-dinitrophenyl hydrazine). The results reveal the pitfalls inherent in using stable nitroxide radicals such as TEMPOL to identify sites of radical formation on hemoproteins.

show abstract

Section: Resultssupporting

confidence: 72%

Spin Scavenging Analysis of Myoglobin Protein-Centered Radicals Using Stable Nitroxide Radicals: Characterization of Oxoammonium Cation-Induced Modifications

Lardinois

Maltby

Medzihradszky

et al. 2009

Chem. Res. Toxicol.

View full text Add to dashboard Cite

show abstract

“…This latter intermediate was isolated and shown to directly decompose into LysCN. Collectively, our results also help to explain why the prior in vitro study by Sivey et al [18, 50, 51] reported LysCN as the overwhelming product formed without 2-AAA. Our studies show similar results when a comparable vast molar excess of oxidant is used (~100-fold or more relative to target).…”

Section: Discussionsupporting

confidence: 76%

Myeloperoxidase-mediated protein lysine oxidation generates 2-aminoadipic acid and lysine nitrile in vivo

Lin

Levison

Buffa

et al. 2017

Free Radical Biology and Medicine

View full text Add to dashboard Cite

Recent studies reveal 2-aminoadipic acid (2-AAA) is both elevated in subjects at risk for diabetes and mechanistically linked to glucose homeostasis. Prior studies also suggest enrichment of protein-bound 2-AAA as an oxidative post-translational modification of lysyl residues in tissues associated with degenerative diseases of aging. While in vitro studies suggest redox active transition metals or myeloperoxidase (MPO) generated hypochlorous acid (HOCl) may produce protein-bound 2-AAA, the mechanism(s) responsible for generation of 2-AAA during inflammatory diseases are unknown. In initial studies we observed that traditional acid- or base-catalyzed protein hydrolysis methods previously employed to measure tissue 2-AAA can artificially generate protein-bound 2-AAA from an alternative potential lysine oxidative product, lysine nitrile (LysCN). Using a validated protease-based digestion method coupled with stable isotope dilution LC/MS/MS, we now report protein bound 2-AAA and LysCN are both formed by hypochlorous acid (HOCl) and the MPO/H2O2/Cl− system of leukocytes. At low molar ratio of oxidant to target protein Nε-lysine moiety, 2-AAA is formed via an initial Nε-monochloramine intermediate, which ultimately produces the more stable 2-AAA end-product via sequential generation of transient imine and semialdehyde intermediates. At higher oxidant to target protein Nε-lysine amine ratios, protein-bound LysCN is formed via initial generation of a lysine Nε-dichloramine intermediate. In studies employing MPO knockout mice and an acute inflammation model, we show that both free and protein-bound 2-AAA, and in lower yield, protein-bound LysCN, are formed by MPO in vivo during inflammation. Finally, both 2-AAA and to lesser extent LysCN are shown to be enriched in human aortic atherosclerotic plaque, a tissue known to harbor multiple MPO-catalyzed protein oxidation products. Collectively, these results show that MPO-mediated oxidation of protein lysyl residues serves as a mechanism for producing 2-AAA and LysCN in vivo. These studies further support involvement of MPO-catalyzed oxidative processes in both the development of atherosclerosis and diabetes risk.

show abstract

“…; Handelman et al . ). The increases in MPO and SOD activity combined with dampened CAT in the FPI sedentary group may indicate that higher levels of H 2 O 2 formed by the SOD‐mediated O 2 .− dismutation persist, increasing H 2 O 2 production.…”

Section: Discussionmentioning

confidence: 97%

“…Regarding the effects of TBI on liver function, it is important to consider that neutrophils produce superoxide anions (O 2 .− ) via NADPH oxidases: O 2 .− is further dismutated by SOD into hydrogen peroxide (H 2 O 2 ) and molecular oxygen. In the presence of CAT, H 2 O 2 is converted into H 2 O and oxygen; otherwise, it can be used as a substrate by MPO to produce hypochlorous acid (HOCl), a highly reactive ROS that is associated with the production of protein carbonyls (Yan et al 1996;Handelman et al 1998). The increases in MPO and SOD activity combined with dampened CAT in the FPI sedentary group may indicate that higher levels of H 2 O 2 formed by the SOD-mediated O 2 .− dismutation persist, increasing H 2 O 2 production.…”

Section: Discussionmentioning

confidence: 99%

Previous physical exercise alters the hepatic profile of oxidative‐inflammatory status and limits the secondary brain damage induced by severe traumatic brain injury in rats

Castro¹,

Ferreira²,

Busanello³

et al. 2017

The Journal of Physiology

View full text Add to dashboard Cite

Although systemic responses have been described after traumatic brain injury (TBI), little is known regarding potential interactions between brain and peripheral organs after neuronal injury. Accordingly, we aimed to investigate whether a peripheral oxidative/inflammatory response contributes to neuronal dysfunction after TBI, as well as the prophylactic role of exercise training. Animals were submitted to fluid percussion injury after 6 weeks of swimming training. Previous exercise training increased mRNA expression of X receptor alpha and ATP-binding cassette transporter, and decreased inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-α and interleukin (IL)-6 expression per se in liver. Interestingly, exercise training protected against hepatic inflammation (COX-2, iNOS, TNF-α and IL-6), oxidative stress (decreases in non-protein sulfhydryl and glutathione, as well as increases in 2',7'-dichlorofluorescein diacetate oxidation and protein carbonyl), which altered hepatic redox status (increases in myeloperoxidase and superoxide dismutase activity, as well as inhibition of catalase activity) mitochondrial function (decreases in methyl-tetrazolium and Δψ, as well as inhibition of citrate synthase activity) and ion gradient homeostasis (inhibition of Na ,K -ATPase activity inhibition) when analysed 24 h after TBI. Previous exercise training also protected against dysglycaemia, impaired hepatic signalling (increase in phosphorylated c-Jun NH2-terminal kinase, phosphorylated decreases in insulin receptor substrate and phosphorylated AKT expression), high levels of circulating and neuronal cytokines, the opening of the blood-brain barrier, neutrophil infiltration and Na ,K -ATPase activity inhibition in the ipsilateral cortex after TBI. Moreover, the impairment of protein function, neurobehavioural (neuromotor dysfunction and spatial learning) disability and hippocampal cell damage in sedentary rats suggests that exercise training also modulates peripheral oxidative/inflammatory pathways in TBI, which corroborates the ever increasing evidence regarding health-related outcomes with respect to a physically active lifestyle.

show abstract

Formation of Carbonyls during Attack on Insulin by Submolar Amounts of Hypochlorite

Cited by 15 publications

References 38 publications

Spin Scavenging Analysis of Myoglobin Protein-Centered Radicals Using Stable Nitroxide Radicals: Characterization of Oxoammonium Cation-Induced Modifications

Spin Scavenging Analysis of Myoglobin Protein-Centered Radicals Using Stable Nitroxide Radicals: Characterization of Oxoammonium Cation-Induced Modifications

Myeloperoxidase-mediated protein lysine oxidation generates 2-aminoadipic acid and lysine nitrile in vivo

Previous physical exercise alters the hepatic profile of oxidative‐inflammatory status and limits the secondary brain damage induced by severe traumatic brain injury in rats

Contact Info

Product

Resources

About