Amperometric Mercurimetric Titration of Sulfhydryl Groups in Biologically Important Substances

Kolthoff, I. M.; Stricks, W.; Morren, Loes

doi:10.1021/ac60086a025

Cited by 106 publications

(38 citation statements)

References 8 publications

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“…Inorganic Hg is highly water-soluble and reacts readily with thiols without requiring excess reagent or long incubations. Due to the high specificity for 2SH groups, complexes, such as Hg(RS) 2 , with a 1:2 stoichiometric ratio are formed [32][33][34]. During our preliminary studies, we have found that under our electrophoretic conditions the only complex formed is Hg(Thiol) 2 .…”

Section: Quantification Of Thiols In Erythrocytes and Plasmamentioning

confidence: 78%

Quantitation of reduced glutathione and cysteine in human immunodeficiency virus‐infected patients

et al. 2004

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Plasma viral load (VL) values and CD4(+) cell count are employed clinically for initiation of therapy in the treatment of patients infected with human immunodeficiency virus (HIV), as previous clinical studies have shown a marked prevalence of acquired immunodeficiency syndrome (AIDS) development in seropositive individuals with VL values over 30 000 copies/mL. Many studies have shown that reduced glutathione (GSH) and cysteine (Cys) deficiency play an important role in the infection. We have developed capillary zone electrophoresis (CZE)-based assays and have used them to investigate the relationship between plasma and intracellular thiol levels and HIV-1 viremia in plasma. Blood samples from healthy volunteers and seropositive patients undergoing different antiretroviral regimes were analyzed in the study. The VL assay was based on CZE-UV detection of viral RNA at 260 nm. Determination of endogenous reduced Cys and GSH was achieved by CZE-UV detection of their mercurial complexes at 200 nm. We found that a decrease in GSH and Cys levels may be associated with disease progress. In fact, reduced GSH and Cys levels appear progressively reduced with increasing VL.

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Section: Quantification Of Thiols In Erythrocytes and Plasmamentioning

confidence: 78%

Quantitation of reduced glutathione and cysteine in human immunodeficiency virus‐infected patients

et al. 2004

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“…A standard curve was performed with each determination, using glutathione freshly dissolved in 1.5 per cent metaphosphoric acid. Such a preparation showed negligible increase in reduced glutathione after reduction at the mercury cathode (16) and gave 90 per cent of its theoretical mercury-combining groups in 0.05 M borax, 0.1 M potassium chloride, when titrated amperometrically with 1 mM mercuric chloride using the rotating platinum electrode (17).…”

Section: Role Of Thiols In Oxidant Drug Actionmentioning

confidence: 99%

“…Total glutathione was determined on a 10 ml aliquot of the metaphosphoric acid filtrate reduced over a mercury cathode in a 50 ml beaker by 40 (17). A mercurycoated platinum wire electrode was used (0.5 cm long, rotated by a synchronous motor).…”

Section: Role Of Thiols In Oxidant Drug Actionmentioning

confidence: 99%

Oxidative Hemolysis and Precipitation of Hemoglobin. Ii. Role of Thiols in Oxidant Drug Action*

Allen¹,

Jandl²

1961

J. Clin. Invest.

203

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In a preceding report (1) it was shown that those redox compounds that cause Heinz body anemias in vivo produce a sequence of changes in vitro in solutions of crystalline hemoglobin culminating in the precipitation of hemoglobin as spherical granules. These granules appear to be identical with Heinz bodies. The sequence of changes produced in hemoglobin by these compounds includes: 1) the formation of methemoglobin, 2) an increase in electrophoretic and chromatographic mobility, 3) the appearance of irreversible hemochromes such as sulfhemoglobin and 4) frank precipitation. It was found that similar changes in hemoglobin were produced rapidly by "simple" oxidants such as ferricyanide and slowly by prolonged incubation of hemoglobin alone under oxygen. Com breakdown by acting as a hydrogen donor in the peroxidative destruction of hydrogen peroxide. The necessity for regenerating GSH in such a mechanism would conceivably explain the hypersusceptibility to the action of oxidant compounds of red cells deficient in glucose or in glucose-6-phosphate dehydrogenase (7), since in the red cell, oxidative glycolysis via the pentose phosphate pathway (8), possibly supplemented by anaerobic glycolysis (9), provides the energy for reducing glutathione. On the other hand, there are certain differences between phenylhydrazine-like compounds and hydrogen peroxide in their action on hemoglobin (1). Phenylhydrazine and related compounds appear to destroy hemoglobin through the formation of a series of oxidant derivatives which may resemble, but are not identical with, hydrogen peroxide.The following studies were conducted in order to explore the participation of thiol groups in the oxidative destruction of hemoglobin. METHODSPreparation of reagents. As described previously (1) buffered solutions of crystalline human hemoglobin were prepared by the method of Drabkin (10), and phenylhydrazine and related compounds were dissolved in isotonic (0.12 M) phosphate buffer, pH 7.4. Unless otherwise stated, glutathione,l an acid, was dissolved immediately before use in physiologic saline [since its reduced form is more stable at a low pH (11)] and was added slowly to buffered solutions of hemoglobin in amounts that did not affect the final pH of the solution. The sulfhydryl-binding compound, sodium p-chloromercuribenzoate2 (PCMB), is a base (probably existing as sodium p-hydroxymercuribenzoate) that is very poorly soluble at a physiologic pH; therefore it too was dissolved in unbuffered saline as a concentrate, which was then added slowly to buffered solutions of hemoglobin.General procedures. Methemoglobin and so-called sulfhemoglobin were measured by the Evelyn-Malloy

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“…Brdicka's reaction is the catalytic reaction produced by dissolving certain amino acids, polypeptides and proteins in a buffered cobalt so lution. This type of polarographic analysis has gained considerable recognition be cause of its use in biochemical studies of native and denatured proteins [2].Amperometric titration, the other method of polarographic analysis used in this study, is performed by adding a known amount of titrant to the solution under in vestigation and then measuring the diffusion current [6], This technique may be applied to the analysis of innumerable substances. In this study it was utilized to determine serum sulfhydryl concentration.…”

mentioning

confidence: 99%

Polarographic Study of Serum from Patients with Lupus Erythematosus

Ogura¹,

Owens²,

Knox³

1967

Dermatology

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Amperometric Mercurimetric Titration of Sulfhydryl Groups in Biologically Important Substances

Cited by 106 publications

References 8 publications

Quantitation of reduced glutathione and cysteine in human immunodeficiency virus‐infected patients

Quantitation of reduced glutathione and cysteine in human immunodeficiency virus‐infected patients

Oxidative Hemolysis and Precipitation of Hemoglobin. Ii. Role of Thiols in Oxidant Drug Action*

Polarographic Study of Serum from Patients with Lupus Erythematosus

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