The mechanism of the copper ion catalyzed autoxidation of cysteine in alkaline medium

Abstract

Instead, a reaction model is proposed, which is based upon the involvement of I thiyl-and a superoxoactivati Cu(II) complex, respectively. These two types of complexes are operative in a chainlike propagation cycle _

Modification of the Ca²⁺ Release System of Skeletal Muscle Sarcoplasmic Reticulum Vesicles via Sulfhydryl Oxidation and Tryptic Proteolysis

“…3) The Ca 2 + release rate induced by Cu 2 + and cysteine appears to be first order with respect to Cu 2 + (Figure 8), as expected for Cu 2 +-catalyzed oxidation (95,117). …”

Development of Novel Redox Systems by Use of Ligand Effect and Its Application to Potentiometry

“…Table 6 summarizes the tolerance limits for foreign ions on the determination of 2 ng cm -3 copper(II). Iron(III) did not interfere even when present in 250-fold excess (500 ng cm -3 ), although most catalytic methods for copper determination [52][53][54][55][56] are subject to interference from a few hundred-fold excess of iron(III). The method is applied to the determination of copper in river water as certified reference material (spiked) issued by the Japan Society for Analytical Chemistry.…”

Role of Amino Thiols as Radical Quenchers in Delayed Chemiluminescence of Luminol Catalyzed by Horseradish Peroxidaset

“…+ 0 2 -+ RSSR + H2O2 (1) luminol + H2O2 HRP aminophthalate + N2 + H2O + by (2) Amino thiols were chosen by taking into account the acid dissociation constant (pKa ,SH) of their mercapto groups. Chemical structures of these thiols (RSH) are shown in Fig.…”

“…On the other hand, the Cu(II)-catalyzed oxidation of amino thiol with oxygen is focused on a model reaction for elucidating the mechanism of the biological oxidation with copperbearing enzymes such as galactose oxidase and diamine oxidase. 2 In the catalytic oxidation, H2O2 is shown to be produced as an intermediate from oxygen .3 In the course of our studies on the application of the HRP-catalyzed luminol CL to the detection of H2O2 formed during the catalytic oxidation of cysteamine, we have found that a CL flash suddenly appeared after a certain dark period from the initiation of the reaction. 4 The delay time and the CL intensity were dependent on the concentrations of Cu(II).…”