Polarographic Investigations of Organic Selenium Compounds. VI. The Polarographic Reduction of Diphenyl Diselenide and Diphenyl Disulphide.

Nygård, Bengt; Isaksson, Torild; Samuelson, Olof; Wagnières, Marc; Williams, D. H.; Bunnenberg, E.; Djerassi, Carl; Records, Ruth

doi:10.3891/acta.chem.scand.20-1710

Cited by 26 publications

(5 citation statements)

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“…Diselenides were shown to be more susceptible to nucleophilic attack than disulfides [84,107]. Furthermore in pK A determination studies selenocysteine exhibited a much higher acidity than cysteine (pK A (Sec) = 5.24-5.63, pK A (Cys) = 8.25) [105,108,109], which suggests at physiological pH the Sec residue will be present largely in its reactive anionic form, the selenolate, while the cysteine residue would remain largely protonated. In pH-dependent titration studies it was also shown that selenocysteine reacted with iodoacetate or iodoacetamide at pH values far below the pK A of the selenol [105].…”

Section: Pk a Nucleophilicity And Reactivitymentioning

confidence: 99%

Selenopeptide chemistry

Muttenthaler¹,

Alewood²

2008

Journal of Peptide Science

145

149

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This review focuses on the chemical aspects of the 21st proteinogenic amino acid, selenocysteine in peptides and proteins. It describes the physicochemical properties of selenium/sulfur and selenocysteine/cysteine based on comprehensive structural (X-ray, NMR, CD) and biological data, and illustrates why selenocysteine is considered the most conservative substitution of cysteine. The main focus lies on the synthetic methods on selenocysteine incorporation into peptides and proteins, including an overview of the selenocysteine building block syntheses for Boc- and Fmoc-SPPS. Selenocysteine-mediated reactions such as native chemical ligation and dehydroalanine formation are addressed towards peptide conjugation. Selenopeptides have very interesting and distinct properties which lead to a diverse range of applications such as structural, functional and mechanistic probes, robust scaffolds, enzymatic reaction design, peptide conjugations and folding tools.

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Section: Pk a Nucleophilicity And Reactivitymentioning

confidence: 99%

Selenopeptide chemistry

Muttenthaler¹,

Alewood²

2008

Journal of Peptide Science

145

149

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“…Electroanalysis of biological selenium species, however, is challenging because of unwanted oxidation and adsorption processes at metallic surfaces. The earliest reported electrochemical studies of the selenocysteine / selenocystine (SeCys / SeC) couple were measured on hanging mercury drop electrodes (HDME) and often in acidic conditions [25][26][27]. Polarographic studies revealed formation of a mercuro-selenocystinate film [27].…”

Section: Introductionmentioning

confidence: 99%

Voltammetric behavior of selenocystine at modified gold substrates

Walker

Karnaukh

Dewan

et al. 2016

Electrochemistry Communications

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The voltammetric response of seleno-L-cystine has been studied at gold substrates under physiological conditions. The reactivity of diselenides is utilized to generate a modified electrode surface, which in turn allows for electroanalysis of solution-based selenium species. Stable and reproducible voltammetry is observed for selenocystine reduction at pH 7 on selenium-modified gold substrates (E mid =-486 mV vs. Ag/AgCl) and is consistent with a diffusionally controlled process. Modification of the gold surface is readily achieved via electrochemical cycling in the presence of a diselenide source at conventional scan rates. These studies afford voltammetric characterization of the selenocystine / selenocysteine redox couple under physiologically relevant conditions and highlight the potential utility of selenium-modified substrates for electroanalysis of chalcogen-containing species.

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“…Its low solubility seems to have hindered electrochemical studies in aqueous solution; in fact, no single report on this compound refers to its electrochemical behavior directly on a bare mercury electrode in aqueous media. However, a few studies in water/organic solvent mixtures can be found. − …”

Section: Ph2s2 On a Bare Mercury Electrodementioning

confidence: 99%

Electroreduction of Diphenyl Disulfide on a Self-Assembled Lipid Monolayer on Mercury

2002

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In the present work, a voltammetric study of permeability and redox behavior of diphenyl disulfide (Ph2S2) through a self-assembled monolayer of dioleoylphosphatidylcholine adsorbed on mercury is carried out; the results are compared with those obtained on a bare electrode; in this case, the reduction of Ph2S2 proceeds in a reversible way with the formation of a mercurial compound. The presence of the monolayer of phospholipid provokes an increase in the process irreversibility. Different mechanisms based on Ph 2S2 adsorption either directly on a mercury drop or on phospholipids heads are proposed. The charge associated with the adsorbed Ph 2S2 electroreduction was employed to calculate its solubility, and the method is compared with semiempirical expressions proposed in the literature for obtaining approximate values of solubility.

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Polarographic Investigations of Organic Selenium Compounds. VI. The Polarographic Reduction of Diphenyl Diselenide and Diphenyl Disulphide.

Cited by 26 publications

References 0 publications

Selenopeptide chemistry

Selenopeptide chemistry

Voltammetric behavior of selenocystine at modified gold substrates

Electroreduction of Diphenyl Disulfide on a Self-Assembled Lipid Monolayer on Mercury

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