Determination and distribution of human plasma selenoproteins

Plecko, Thomas; Nordmann, S.; Rükgauer, M.; Kruse-Jarres, J. D.

doi:10.1007/s002160051236

Cited by 23 publications

(21 citation statements)

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“…Combined with Se present in 46-56 kDa band that may be an isoform of selenoprotein P, albumin and selenoprotein P can take about 58-63% of total recovered Se. The result is similar to that reported by Harrison [13] and Plecko [14]. (In conventional Sephadex gel chromatography, these two bands can hardly be separated.)…”

Section: Selenium Distribution In Human Serumsupporting

confidence: 91%

“…Albumin has so far not being reported as a specific selenoprotein. It was reported that Se can incorporate to albumin in form of selenomethionine which replaces the methionine in a non-specific and unregulated manner [14,19,20], or in form of selenide which binds to one of its 17 disulfide bonds [21,22]. Since selenide would be lost in the process of SDS-PAGE operation, it is suggested that the Se binding should be in form of selenomethionine in albumin.…”

Section: Calibration Of Se Determinationmentioning

confidence: 99%

“…It is the only selenoprotein found containing multiple selenocycteine residues [23]. It takes from 39 to 69% of total selenium in human plasma and the percentage distribution depends on human Se nutritional state [13,14,19]. Accordingly, selenoprotein P could also be present in the band of 57-74 kDa in Fig.…”

Section: Calibration Of Se Determinationmentioning

confidence: 99%

“…By combining affinity chromatography with electrothermal atomic absorption spectroscopy, selenium distribution among albumin, selenoprotein P and plasma GSH-Px in human plasma or serum was investigated rapidly and conveniently [13,14]. But affinity chromatography as well as gel filtration can be used to separate only a group of proteins from a mixture, and they suffer from low resolution for protein separation.…”

Section: Introductionmentioning

confidence: 99%

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Separation and detection of selenium-containing proteins in human serum

Gao¹,

Wang²

2000

Fresenius' Journal of Analytical Chemistry

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Selenium-containing proteins or their subunits in human serum were separated and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the amount of selenium in each protein band was determined by HPLC with a fluorescence detector after derivatization with 2,4-diaminonaphthalene (DAN). This procedure provides a detection limit of 0.06 ng in a linear range of 0-1.5 ng. A protein is defined as a selenium-containing protein if its mean Se content exceeds twice the detection limit (0.12 ng) and twice the standard deviation of three replicates in sample determination. At least 4 selenium-containing bands with apparent molecular masses of 57-74, 46-56, 40-42 and 21-22 kDa could be detected from human serum collected from 4 volunteers.

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Section: Selenium Distribution In Human Serumsupporting

confidence: 91%

Section: Calibration Of Se Determinationmentioning

confidence: 99%

Section: Calibration Of Se Determinationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Separation and detection of selenium-containing proteins in human serum

Gao¹,

Wang²

2000

Fresenius' Journal of Analytical Chemistry

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“…A deficiência de selênio no organismo, um nutriente essencial, apresenta uma diminuição na atividade desta enzima em sua forma reduzida, e tem sido associada com alterações no metabolismo celular 20,21 . Em um trabalho recente 22 , foi determinada a distribuição de selênio em plasma humano por cromatografia líquida, onde as maiores frações deste elemento encontram-se associadas junto à enzima GSH-Px e albumina. Neste sentido, um controle dos níveis de glutationa (GSH) torna-se importante, já que níveis normais de GSH em células de mamíferos 3 estão na faixa de 0,5 a 10 mmol L -1 .…”

Section: Introductionunclassified

Sistema antioxidante envolvendo o ciclo metabólico da glutationa associado a métodos eletroanalíticos na avaliação do estresse oxidativo

Júnior¹,

Höehr²,

Vellasco³

et al. 2001

Quím. Nova

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Recebido em 27/1/00; aceito em 12/5/00 ANTIOXIDANT SYSTEM INVOLVING THE GLUTATHIONE METABOLIC CYCLE ASSOCIATED TO ELECTROANALYTICAL METHODS IN THE OXIDATIVE STRESS EVALUATION. The most relevant advances on the analytical applications of glutathione determination based on glutathione redox cycle and the antioxidant system are given. The main enzymes that participate of the glutathione metabolism are the glutathione peroxidase and glutathione reductase. The glutathione peroxidase has a major role in the removal of hydrogen peroxide and lipid peroxides from the cells. These enzymes, operating in tandem with catalase and superoxide dismutase promote a scavenging of oxyradical products in tissues minimizing damages caused by these species. Reduced glutathione is the major intracellular thiol found in mammals and changes in the glutathione concentration in biological fluids or tissues may provide a useful marker in certain disorders like hemolytic anemia, myocardial oxidative stress and in the investigation of some kinds of cancers. Particular attention is devoted to the main advantages supplied by biosensors in which there is an incorporation of bioactive materials for the glutathione determination. The correlation between stability and sensitivity of some reduced glutathione electrochemical sensors is discussed.Keywords: glutathione; electroanalysis; bioelectrochemistry; oxidative stress. Divulgação Quim. Nova, Vol. 24, No. 1, 112-119, 2001. INTRODUÇÃOA incidência de doenças relacionadas a processos cancerígenos no organismo, envolvendo a formação de espéci-es reativas de oxigênio tais como peróxido de hidrogênio e o radical hidroxila, vem merecendo especial atenção nos últimos anos. Existe uma importante correlação entre os níveis de glutationa em sua forma reduzida e os mecanismos enzimáticos de defesa. Esta observação tem promovido uma série de estudos clínicos sobre a interdependência entre o aumento dos ní-veis de glutationa no plasma sangüíneo e doenças cancerígenas em determinados órgãos vitais como rins e pulmões 1,2 . Glutationa, um tripeptídeo (γ-L-glutamil-L-cisteinil-glicina), existe no organismo em suas formas reduzida (GSH) e oxidada (GSSG), atuando direta ou indiretamente em muitos processos biológicos importantes, incluindo a síntese de proteínas, metabolismo e proteção celular 3 . Em particular, problemas na sín-tese e metabolismo da glutationa estão associados a algumas doenças, nas quais os níveis de glutationa e das enzimas que atuam no seu metabolismo podem ser bastante significativos no diagnóstico de alguns tipos de câncer, bem como em outras doenças relacionadas ao estresse oxidativo 4-6 . Mudanças na concentração deste tripeptídeo podem ser um indicador útil em certas desordens fisiológicas como anemias causadas por infecção ou seguidas pela administração de algumas drogas oxidantes 7 , no monitoramento da eficácia de alguns tratamentos usando N-acetil-L-cisteína (NAC) durante o metabolismo do paracetamol 8 , no tratamento de pacientes com artrite reumatróide 9 e na investigação do estresse ...

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Reaction Mechanism of Selenate(IV) Ions with Several Thiols in Aqueous Media

Forastiere

Borghi

Morando

2007

Helvetica Chimica Acta

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In several enzymatic systems, selenium (an essential element commonly incorporated as sodium selenite to the human diet) is bonded through a mercapto group of a cysteine residue. The reaction of Se IV (as selenite) with different thiols in aqueous media was studied to increase the information about the mechanism of the enzyme reaction. The influence of the reagents concentration on the reaction rate and temporal spectral changes was analyzed. A complex with a UV maximum between 270 and 290 nm was formed, which quickly decayed when the thiol concentration was increased. The proposed reaction mechanism includes a fast Se IV -thiol association step followed by two parallel steps (one is first-order in the complex and the other one is globally second-order). Kinetics and equilibrium constants were obtained, and the rate dependence of the thiol oxidation on the Se IV concentration was modelled for all thiols tested. Very good agreement between the experimental and calculated curves was observed. The role of selenium as an essential element was demonstrated in 1954 when it was observed that low ingestion levels were associated with cardiopathies, specially in children, and with diseases in cattle [7]. It was reported that this alterations were reverted by addition of sodium selenite [8] to the diet, and numerous commercial products exist today to supply this element.Selenium is incorporated in the proteins [9] glutathione peroxidase (25%), selenoprotein P (68%), whose biological function is not yet completely understood [10] [11], and albumin A (7%) [12]. Glutathione peroxidase [13] is the bestcharacterized enzymatic system containing selenium. It is formed by four subunits bonded to a Se-atom as a selenocysteine residue. This enzyme transforms glutathione into the oxidized form, with the corresponding reduction of hydrogen peroxide and peroxides formed during the lipid oxidation in membranes. Therefore, it is nowadays used in antioxidant formulations.It is well known that the paths followed by selenate and selenite in the organism are different. Both can be used as a nutritional supplement, but whereas selenite,

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Determination and distribution of human plasma selenoproteins

Cited by 23 publications

References 0 publications

Separation and detection of selenium-containing proteins in human serum

Separation and detection of selenium-containing proteins in human serum

Sistema antioxidante envolvendo o ciclo metabólico da glutationa associado a métodos eletroanalíticos na avaliação do estresse oxidativo

Reaction Mechanism of Selenate(IV) Ions with Several Thiols in Aqueous Media

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