The crystal structure of the CopC protein from Pseudomonas fluorescens reveals amended classifications for the CopC protein family.

The bacterial CopC family of proteins are periplasmic copper binding proteins that act in copper detoxification. These proteins contain Cu(I) and/or Cu(II) binding sites, with the family that binds Cu(II) only the most prevalent, based on sequence analyses. Here we present three crystal structures of the CopC protein from Pseudomonas fluorescens (Pf-CopC) that include the wild type protein bound to Cu(II) and two variant proteins, where Cu(II) coordinating ligands were mutated, in Cu-free states.

Molecular Mechanisms of Glutaredoxin Enzymes: Versatile Hubs for Thiol-Disulfide Exchange between Protein Thiols and Glutathione.

The tripeptide glutathione (GSH) and its oxidized form glutathione disulfide (GSSG) constitute a key redox couple in cells. In particular, they partner protein thiols in reversible thiol-disulfide exchange reactions that act as switches in cell signaling and redox homeostasis. Disruption of these processes may impair cellular redox signal transduction and induce redox misbalances that are linked directly to aging processes and to a range of pathological conditions including cancer, cardiovascular diseases and neurological disorders.

The Human Amyloid Precursor Protein Binds Copper Ions Dominated by a Picomolar-Affinity Site in the Helix-Rich E2 Domain.

A manifestation of Alzheimer's disease (AD) is the aggregation in the brain of amyloid β (Aβ) peptides derived from the amyloid precursor protein (APP). APP has been linked to modulation of normal copper homeostasis, while dysregulation of Aβ production and clearance has been associated with disruption of copper balance. However, quantitative copper chemistry on APP is lacking, in contrast to the plethora of copper chemistry available for Aβ peptides.

Glutaredoxins employ parallel monothiol-dithiol mechanisms to catalyze thiol-disulfide exchanges with protein disulfides.

Glutaredoxins (Grxs) are a family of glutathione (GSH)-dependent thiol-disulfide oxidoreductases. They feature GSH-binding sites that directly connect the reversible redox chemistry of protein thiols to the abundant cellular nonprotein thiol pool GSSG/GSH. This work studied the pathways for oxidation of protein dithiols P(SH) and reduction of protein disulfides P(SS) catalyzed by HsGrx1 and EcGrx1.

C-F bond activation of trifluoroethanol and trifluoroacetic acid catalysed by the dimolybdate anion, [MoO(F)].

Two gas-phase catalytic cycles involving C-F bond activation of trifluoroethanol and trifluoroacetic acid were detected by multistage mass spectrometry experiments. A binuclear dimolybdate centre [MoO(F)] acts as the catalyst in each cycle. The first cycle, entered via the reaction of [MoO(OH)] with trifluoroethanol and elimination of water to form [MoO(OCHCF)], proceeds via four steps: (1) oxidation of the alkoxo ligand and its elimination as aldehyde; (2) reaction of [MoO(OH)] with trifluoroethanol and elimination of water to form [MoO(OCHCF)]; (3) decomposition of the alkoxo ligand via loss of 1,1 difluoroethene; and (4) reaction of [MoO(F)] with a second equivalent of trifluoroethanol to regenerate MoO(OCHCF)].