Tekla Structures License Server Administrator Guide. 1/3 2/3. Tekla Structures 16.0 Installation Guide Microsoft Windows Server OS 9 Windows Server.
How to uninstall software 1. 7. (Windows 95/98/NT4/2000/XP)1. 1. 19. 0K 8. 1. Tekla Applications 16.0 Installation Guide Microsoft Windows NT.Molecular Mechanisms of De-Novo Recycling and De-novo Synthesis of the Glutathione Redox Pair.
The glutathione redox pair (GSH-GSSG) is central to the regulation of cellular redox status, and is particularly important in cellular defense against oxidative stress. Its concentration is determined by the equilibrium between de-novo synthesis and de-novo recycling. The latter is mediated by glutathione peroxidase (GPx) and reductase (GR). We recently determined the molecular structures of the human GR (hGR) and GPx (hGPx) protein monomers. This report describes the molecular mechanisms by which these proteins function as two half-reactions. We propose that the hGR reaction mechanism involves electron transfer from NADPH to the heme prosthetic group of the hGR apo monomer. The resulting semiquinone radical (hGR-Q) is oxidized by the substrate glutathione to form the catalytically competent hGR-S2. At the expense of an overall hGR turnover rate of ∼0.3 s-1, the ensuing hGR-S2 species is converted to a fully oxidized form. The hGR-S2 thus formed then binds back to the apo monomer. The reduction of the NADPH-bound hGR-S2 species by the substrate glutathione is coupled to the generation of NADP(+) and the reduction of hGR-Q. Consequently, the hGR-S2 form is a reversible NADPH oxidase activity. We propose that the hGPx reaction mechanism involves electron transfer to the enzyme's NADPH cofactor. The resulting hGPx-Q is oxidized by the substrate thiol in the catalytic pocket to form the fully oxidized hGPx-S3. This is in turn oxidized by H2O2 to yield the superoxide anion O2- in a slow two-electron transfer process. We propose that the O2- generation is driven by the thermodynamically be359ba680
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