protein carbonyl Dotaz Zobrazit nápovědu
Enzymatic carbonyl reduction means the formation of a hydroxy function out of a ketone or aldehyde moiety and applies for the metabolism of physiological (endogenous) or xenobiotic (exogenous) molecules. As for endogenous substrates, carbonyl reduction is often part of a reversible oxidoreductase process and involves the activation or inactivation of important signal molecules like steroids, prostaglandins, retinoids and biogenic amines. These reactions are carried out by NAD(P)(H)-dependent dehydrogenases belonging to two protein superfamilies, the aldo-keto reductases (AKR) and the short-chain dehydrogenases/reductases (SDR). With regard to exogenous substrates, carbonyl reduction of xenobiotics is generally a "one-way" detoxification reaction, since the resulting alcohol is easier to conjugate and to eliminate. Interestingly, the participating enzymes do also belong to the AKR and SDR superfamilies. Moreover, some enzymes from the two protein superfamilies exhibit pluripotency in that they are able to catalyze the oxidoreduction of endobiotics but do also function in the reductive metabolism of carbonyl group bearing xenobiotics. A special case are carbonyl reductases per se which belong to the SDR superfamily and whose substrates or physiological roles are not quite clear. Usually, carbonyl reductases have a broad and diverse substrate spectrum for xenobiotics, however, for some of them a specific physiological function has been speculated. In the human genome, three SDR genes have been identified to code for the carbonyl reductases CBR1 (SDR21C1), CBR3 (SDR21C2) and CBR4 (SDR45C1). The present review summarizes the current knowledge on these enzymes with special emphasis on their role as a defence system against toxicants, as well as their possible physiological function and medical application. In detail, we have screened the recent literature on these three enzymes with regard to endogenous and exogenous substrates, their three-dimensional structure, tissues specific expression, polymorphisms, transcriptional regulation, occurrence in pathological states, and their possible association with cancer. Combined, this review contributes to understanding the complex nature and biological roles(s) of the human carbonyl reductases CBR1, CBR3 and CBR4.
- MeSH
- alkoholoxidoreduktasy chemie genetika metabolismus MeSH
- exprese genu MeSH
- lidé MeSH
- mitochondriální proteiny chemie genetika metabolismus MeSH
- NAD(P)H dehydrogenasa (chinon) chemie genetika metabolismus MeSH
- polymorfismus genetický MeSH
- xenobiotika metabolismus toxicita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Background. Studies have shown that oxidative stress increases with increasing human age. Protein carbonyl accumulation is an indicator of oxidative damage to proteins during aging in cells and tissues. The present study is focused on the relationship between human age and protein oxidation in erythrocyte membranes in a healthy Indian population. Materials and Methods. The sample included healthy human subjects (n = 49) between the ages of 17 to 80 years. Their blood was collected and assayed spectrophotometrically for oxidative protein damage in terms of protein carbonyls and plasma antioxidant capacity in terms of FRAP. Results. Protein carbonyl content was found to increase in an age-related pattern indicating an increase in oxidative protein damage in older subjects (p <0.0001, r = 0.8269). There was also a significant negative correlation between protein oxidation and plasma antioxidant capacity measured in terms of ferric reducing antioxidant potential (FRAP) values (p<0.0001; r = -0.8695). Conclusion. Our results substantiate the occurrence of oxidative stress during human aging. Elevated erythrocyte membrane carbonyl levels found with increasing age in this study may be viewed as a biomarker for aging.
- MeSH
- antioxidancia metabolismus MeSH
- dospělí MeSH
- erytrocytární membrána metabolismus MeSH
- karbonylace proteinů MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- oxidační stres MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- spektrofotometrie MeSH
- stárnutí metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
Myelodysplastic syndromes (MDS) represent a heterogeneous group of pre-leukemic disorders, characterized by ineffective hematopoiesis and the abnormal blood cell development of one or more lineages. Oxidative stress, as an important factor in the carcinogenesis of onco-hematological diseases, is also one of the known factors involved in the pathogenesis of MDS. An increase of reactive oxygen species (ROS) may lead to the oxidation of DNA, lipids, and proteins, thereby causing cell damage. Protein carbonylation caused by ROS is defined as an irreversible post-translational oxidative modification of amino acid side chains, and could play an important role in signaling processes. The detection of protein carbonyl groups is a specific useful marker of oxidative stress. In this study, we examined 32 patients divided into three different subtypes of MDS according to the World Health Organization (WHO) classification criteria as refractory anemia with ringed sideroblasts (RARS), refractory cytopenia with multilineage dysplasia (RCMD), refractory anemia with excess blasts-1,2 (RAEB-1,2). We found significant differences in protein carbonylation between the group of all MDS patients and healthy controls (P=0.0078). Furthermore, carbonylated protein levels were significantly elevated in RARS patients compared to healthy donors (P=0.0013) and to RCMD patients (P=0.0277). We also found a significant difference in the total iron binding capacity (TIBC) between individual subgroups of MDS patients (P=0.0263). Moreover, TIBC was decreased in RARS patients compared to RCMD patients (P=0.0203). TIBC moderately negatively correlated with carbonyl levels (r=-0.5978, P=0.0054) in the MDS patients as a whole. Additionally we observed changes in the carbonylated proteins of RARS patients in comparison with healthy controls and their negative controls. Using tandem mass spectrometry (LC-MS/MS) we identified 27 uniquely carbonylated proteins of RARS patients, which were generated by ROS and could influence the pathophysiology of low-risk MDS. These data indicate that increased protein carbonylation is related with RARS as low-risk MDS subgroup. We suggest that this type of post-translational modification in MDS disease is not "only" a consequence of oxidative stress, but also plays an active role in the pathophysiology and iron metabolism within the RARS subgroup of MDS. Measurement of plasma carbonyl levels and the isolation of carbonylated plasma proteins, followed by their identification, could serve as a potential diagnostic and prognostic tool in MDS.
- MeSH
- dospělí MeSH
- karbonylace proteinů MeSH
- krevní proteiny metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- myelodysplastické syndromy diagnóza metabolismus MeSH
- oxidační stres MeSH
- prognóza MeSH
- reaktivní formy kyslíku metabolismus MeSH
- refrakterní anemie MeSH
- senioři MeSH
- tandemová hmotnostní spektrometrie MeSH
- vazba proteinů MeSH
- železo metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Oxidative and carbonyl stress may, on one hand, contribute to the progression of cancer, on the other hand, they may have some antiproliferative effects. We examined serum levels of AGEs (advanced glycation end-products), CML (carboxymethyllysine) and AOPP (advanced oxidation protein products) in 86 patients with breast cancer subdivided based on the clinical stage (TNM classification), histologic grading, expression of hormonal and C-erb B2 receptors and in 14 healthy age-matched women as controls. Breast cancer patients had higher serum concentrations of AGEs (325,581 +/- 66,037 vs. 271,322 +/- 34,826 AU, p < 0.01) even in the early stage of the disease; patients with advanced breast cancer (stage III and IV) had significantly higher both AGEs and AOPP (113.0 +/- 44.9 vs. 78.1 +/- 28.4 micromol/l, p < 0.05) levels, not only compared to controls, but also compared to stages I and II. Serum levels of AOPP were higher in patients having only weakly positive expression of C-erb 2/Her-neu compared to controls and the patients having the highest C-erb2/Her-neu expression. Serum concentrations of AGEs in patients with breast cancer correlated with the age and also with the serum concentration of AOPP. In conclusion: breast cancer patients had an early increase of AGEs (marker of the carbonyl stress) followed by further increase of AGEs and elevation of AOPP (marker of oxidative stress) in patients with progressive disease. As the clinical significance of these observations is currently uncertain further studies are clearly warranted, especially with respect to their potential therapeutic implications.
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- estrogeny metabolismus MeSH
- financování organizované MeSH
- karbonylace proteinů MeSH
- krevní proteiny analýza MeSH
- lidé středního věku MeSH
- lidé MeSH
- lysin analogy a deriváty krev MeSH
- nádory prsu diagnóza krev terapie MeSH
- oxidace-redukce MeSH
- oxidační stres MeSH
- produkty pokročilé glykace krev MeSH
- prognóza MeSH
- receptor erbB-2 metabolismus MeSH
- staging nádorů MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- srovnávací studie MeSH
Tiaprofenic acid is a widely used anti-inflammatory drug; however, the reductive metabolism of tiaprofenic acid is not yet well understood. Here, we compared the reduction of tiaprofenic acid in microsomes and cytosol from the human liver. The microsomes exhibited lower Km value toward tiaprofenic acid than the cytosol (Km = 164 ± 18 μM vs. 569 ± 74 μM, respectively), whereas the cytosol showed higher specific activity during reduction than the microsomes (Vmax = 728 ± 52 pmol mg of protein-1 min-1 vs. 285 ± 11 pmol mg of protein-1 min-1, respectively). Next, a panel of recombinant carbonyl reducing enzymes from AKR and SDR superfamilies has been studied to find the enzymes responsible for the cytosolic reduction of tiaprofenic acid. CBR1 was identified as the reductase of tiaprofenic acid with high specific activity (56,965 ± 6741 pmol mg of protein-1 min-1). Three other enzymes, AKR1A1, AKR1B10, and AKR1C4, were also able to reduce tiaprofenic acid, but with very low activity. Thus, CBR1 was shown to be a tiaprofenic acid reductase in vitro and was also suggested to be the principal tiaprofenic acid reductase in vivo.
- MeSH
- alkoholoxidoreduktasy chemie genetika metabolismus MeSH
- biokatalýza MeSH
- cytosol enzymologie MeSH
- dehydrogenasy/reduktasy s krátkým řetězcem chemie genetika metabolismus MeSH
- játra enzymologie metabolismus MeSH
- kinetika MeSH
- lidé MeSH
- mikrozomy enzymologie MeSH
- propionáty chemie metabolismus MeSH
- rekombinantní proteiny biosyntéza chemie izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Response of pigs to irradiation manifested by production of protein carbonyls and adaptable enzymes was studied in two experiments. In one experiment, 10 mixed-sex pigs were exposed to 0.5 Gy whole body (60)Co irradiation. In the other experiment, another batch of 10 pigs was exposed to 1.0 Gy half-body irradiation. Unlike those exposed to half-body irradiation, the pigs exposed to whole-body irradiation showed significant increase in protein carbonyls by 73%, and a decrease in cholesterol by 25.7%, compared to the control group. In both cases of dose-dependent irradiation exposure, pigs showed a decrease in alanine aminotransferase activity compared with the control group. At the dose of 1 Gy, ALT activity decreased significantly by 27.7%. Aspartate aminotransferase activity in pigs after half-body irradiation decreased significantly by 65.5%. Although low doses of ionizing radiation were applied, monitoring of the above biochemical parameters helped define the pigs' biological response.
Carnosine is a performance-enhancing food supplement with a potential to modulate muscle energy metabolism and toxic metabolites disposal. In this study we explored interrelations between carnosine supplementation (2 g/day, 12 weeks) induced effects on carnosine muscle loading and parallel changes in (i) muscle energy metabolism, (ii) serum albumin glycation and (iii) reactive carbonyl species sequestering in twelve (M/F=10/2) sedentary, overweight-to-obese (BMI: 30.0+/-2.7 kg/m2) adults (40.1+/-6.2 years). Muscle carnosine concentration (Proton Magnetic Resonance Spectroscopy; 1H-MRS), dynamics of muscle energy metabolism (Phosphorus Magnetic Resonance Spectroscopy; 31P-MRS), body composition (Magnetic Resonance Imaging; MRI), resting energy expenditure (indirect calorimetry), glucose tolerance (oGTT), habitual physical activity (accelerometers), serum carnosine and carnosinase-1 content/activity (ELISA), albumin glycation, urinary carnosine and carnosine-propanal concentration (mass spectrometry) were measured. Supplementation-induced increase in muscle carnosine was paralleled by improved dynamics of muscle post-exercise phosphocreatine recovery, decreased serum albumin glycation and enhanced urinary carnosine-propanal excretion (all p<0.05). Magnitude of supplementation-induced muscle carnosine accumulation was higher in individuals with lower baseline muscle carnosine, who had lower BMI, higher physical activity level, lower resting intramuscular pH, but similar muscle mass and dietary protein preference. Level of supplementation-induced increase in muscle carnosine correlated with reduction of protein glycation, increase in reactive carbonyl species sequestering, and acceleration of muscle post-exercise phosphocreatine recovery.
- MeSH
- dospělí MeSH
- fosfokreatin metabolismus MeSH
- karnosin * metabolismus farmakologie MeSH
- kosterní svaly metabolismus MeSH
- lidé MeSH
- Maillardova reakce MeSH
- potravní doplňky MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
