کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10738026 | 1046678 | 2011 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Myoglobin-H2O2 catalyzes the oxidation of β-ketoacids to α-dicarbonyls: Mechanism and implications in ketosis
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کلمات کلیدی
nuclear factor κβAdvanced glycated end productsMNPDMPO5,5′-dimethyl-1-pyrroline N-oxideacetoacetateRAGEMAAAGEsHRPGSHCATo-Phenylenediamine - o-phenylenediamineopd - UPDELISA - تست الیزاEnzyme-linked immunosorbent assay - تست الیزاElectron paramagnetic resonance - تشدید پارامغناطیس الکترونEPR - تشدید پارامغناطیس الکترونtumor necrosis factor α - تومور نکروز عامل αDiacetyl - دیاکتیلFree radicals - رادیکال آزادSOD - سدSuperoxide dismutase - سوکسوکس دیسموتازTNF-α - فاکتور نکروز توموری آلفاMethylglyoxal - متیل گلی اکسالMyoglobin - میوگلوبینtert-butyl hydroperoxide - هیدروپراکسید تری بوتیلHorseradish peroxidase - پراکسیداز هوررادیشCatalase - کاتالازreduced glutathione - کاهش گلوتاتیونKetosis - کتوزhigh performance liquid chromatography - کروماتوگرافی مایع با کارایی بالاHPLC - کروماتوگرافی مایعی کارا
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
سالمندی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Acetoacetate (AA) and 2-methylacetoacetate (MAA) are accumulated in metabolic disorders such as diabetes and isoleucinemia. Here we examine the mechanism of AA and MAA aerobic oxidation initiated by myoglobin (Mb)/H2O2. We propose a chemiluminescent route involving a dioxetanone intermediate whose thermolysis yields triplet α-dicarbonyl species (methylglyoxal and diacetyl). The observed ultraweak chemiluminescence increased linearly on raising the concentration of either Mb (10-500 μM) or AA (10-100 mM). Oxygen uptake studies revealed that MAA is almost a 100-fold more reactive than AA. EPR spin-trapping studies with MNP/MAA revealed the intermediacy of an α-carbon-centered radical and acetyl radical. The latter radical, probably derived from triplet diacetyl, is totally suppressed by sorbate, a well-known quencher of triplet carbonyls. Furthermore, an EPR signal assignable to MNP-AA
- adduct was observed and confirmed by isotope effects. Oxygen consumption and α-dicarbonyl yield were shown to be dependent on AA or MAA concentrations (1-50 mM) and on H2O2 or tert-butOOH added to the Mb-containing reaction mixtures. That ferrylMb is involved in a peroxidase cycle acting on the substrates is suggested by the reaction pH profiles and immunospin-trapping experiments. The generation of radicals and triplet dicarbonyl products by Mb/H2O2/β-ketoacids may contribute to the adverse health effects of ketogenic unbalance.
- adduct was observed and confirmed by isotope effects. Oxygen consumption and α-dicarbonyl yield were shown to be dependent on AA or MAA concentrations (1-50 mM) and on H2O2 or tert-butOOH added to the Mb-containing reaction mixtures. That ferrylMb is involved in a peroxidase cycle acting on the substrates is suggested by the reaction pH profiles and immunospin-trapping experiments. The generation of radicals and triplet dicarbonyl products by Mb/H2O2/β-ketoacids may contribute to the adverse health effects of ketogenic unbalance.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Free Radical Biology and Medicine - Volume 51, Issue 3, 1 August 2011, Pages 733-743
Journal: Free Radical Biology and Medicine - Volume 51, Issue 3, 1 August 2011, Pages 733-743
نویسندگان
Douglas Ganini, Marcelo Christoff, Marilyn Ehrenshaft, Maria B. Kadiiska, Ronald P. Mason, Etelvino J.H. Bechara,