It has been reported that rat liver cystathionase (EC 4.4.1 .l) is inhibited by butanedione and suggested that the a-carboxyl groups of the substrates (L-homoserine and L-cysteine, respectively) are bound to the protein through arginine residues [I]. To support the concept that specific residues are critical or even essential to enzyme activities, we carried out experiments using phenylglyoxal,...

In vivo inactivation of cystathionine gamma-lyase by D,L-propargylglycine, a suicide inhibitor, was found to be less profound in rat kidney than in the liver. We investigated the cause of this difference using rat tissues. We fractionated kidney extract to characterize the substance which protected enzyme, and found that cysteine exhibits protecting action. Addition of 0.3 mM L-cysteine to the ...

The surface of glassy carbon (GC) electrode has been modified by oxidation of L-cysteine. The covalent modified GC electrode with L-Cysteine has been studied, according the supporting electrolyte used. Favourable interactions between the L-cysteine film and DA enhance the current response compared to that at the Nafion GC and bare GC electrodes, achieving better performances than those other el...

A cysteine desulfhydrase was purified 110-fold from the green alga Chlorella using conven­ tional techniques. The isolated cysteine desulfhydrase was specific for D-cysteine having no activity towards L-cysteine. Dand L-cysteine desulfhydrase activities can be separated using DEAE-cellulose chromatography techniques. The isoelectric point o f this enzyme was deter­ mined to be around a pH o f 4...

Previous in vivo studies indicate that locally injected redox-modulating agents can sensitize polymodal peripheral skin nociceptors resulting in acute changes in pain perception. Since endogenous thiol-modifying redox agents are normally present in the interstitial tissue, and could be found in higher concentration in certain conditions (e.g., tissue injury, inflammation, and ischemia), we desi...

The oxidation of L-cysteine by horseradish peroxidase in the presence of oxygen forms a thiyl free radical as demonstrated with the spin-trapping ESR technique. Reactions of this thiyl free radical result in oxygen consumption, which is inhibited by the spin trap 5,5'-dimethyl-1-pyrroline-N-oxide. Cysteine sulfinic acid, a cysteine metabolite, is a poorer substrate for horseradish peroxidase th...

The C/EBP Homologous Protein (CHOP) is a nuclear protein that is integral to the unfolded protein response culminating from endoplasmic reticulum stress. Previously, CHOP was shown to comprise extensive disordered regions and to self-associate in solution. In the current study, the intrinsically disordered nature of this protein was characterized further by comprehensive in silico analyses. Usi...

Multistep proteolytic mechanisms are essential for converting proprotein precursors into active peptide neurotransmitters and hormones. Cysteine proteases have been implicated in the processing of proenkephalin and other neuropeptide precursors. Although the papain family of cysteine proteases has been considered the primary proteases of the lysosomal degradation pathway, more recent studies in...