Search results for " phosphorylation"

A Superoxovanadium(V) Complex Linking the Peroxide and Dioxygen Chemistry of Vanadium.

2001

A missing link: A superoxovanadium(V) complex is the first reaction intermediate in the oxidative conversion of a peroxovanadium(V) complex into a vanadyl(IV) complex and molecular oxygen. The superoxo species appears also to play an essential role in the formation of the peroxovanadium(V) complex from the vanadyl(IV) complex and molecular oxygen.

Cover Picture: Photo-Chromium: Sensitizer for Visible-Light-Induced Oxidative C−H Bond Functionalization-Electron or Energy Transfer? (ChemPhotoChem …

2017

Forever Young: Structural Stability of Telomeric Guanine Quadruplexes in the Presence of Oxidative DNA Lesions**

2021

International audience; Human telomeric DNA, in G-quadruplex (G4) conformation, is characterized by a remarkable structural stability that confers it the capacity to resist to oxidative stress producing one or even clustered 8-oxoguanine (8oxoG) lesions. We present a combined experimental/computational investigation, by using circular dichroism in aqueous solutions, cellular immunofluorescence assays and molecular dynamics simulations, that identifies the crucial role of the stability of G4s to oxidative lesions, related also to their biological role as inhibitors of telomerase, an enzyme overexpressed in most cancers associated to oxidative stress.

ChemInform Abstract: Enantioselective Palladium-Catalyzed Oxidative β,β-Fluoroarylation of α,β-Unsaturated Carbonyl Derivatives.

2016

The site-selective palladium-catalyzed three-component coupling of deactivated alkenes, arylboronic acids, and N-fluorobenzenesulfonimide is disclosed herein. The developed methodology establishes a general, modular, and step-economical approach to the stereoselective β-fluorination of α,β-unsaturated systems.

ChemInform Abstract: Versatile Oxidative Approach to Carbazoles and Related Compounds Using MoCl5.

2014

Oxidative intramolecular coupling of tertiary amines with at least two electron-rich arenes gives carbazoles in good to excellent yields.

ChemInform Abstract: Powerful Fluoroalkoxy Molybdenum(V) Reagent for Selective Oxidative Arene Coupling Reaction.

2014

A novel dinuclear fluoroalkoxy Mo(V)-complex is efficient as reagent for the oxidative arene coupling of electron-rich arenes with superior reactivity compared to MoCl5 and MoCl5/TiCl4.

Post-Translational Regulation of CYP450s Metabolism As Revealed by All-Atoms Simulations of the Aromatase Enzyme.

2019

Phosphorylation by kinases enzymes is a widespread regulatory mechanism able of rapidly altering the function of target proteins. Among these are cytochrome P450s (CYP450), a superfamily of enzymes performing the oxidation of endogenous and exogenous substrates thanks to the electron supply of a redox partner. In spite of its pivotal role, the molecular mechanism by which phosphorylation modulates CYP450s metabolism remains elusive. Here by performing microsecond-long all-atom molecular dynamics simulations, we disclose how phosphorylation regulates estrogen biosynthesis, catalyzed by the Human Aromatase (HA) enzyme. Namely, we unprecedentedly propose that HA phosphorylation at Y361 markedl…

Neuroglobin and cytoglobin:two new entries in the hemoglobin superfamily.

2004

Abstract: Neuroglobin (Ngb) and cytoglobin (Cygb) are two newly discovered intracellular members of the vertebrate hemoglobin (Hb) family. Ngb, predominantly expressed in nerve cells, is of ancient evolutionary origin and is homologous to nerve-globins of invertebrates. Cygb, present in many different tissues, shares common ancestry with myoglobin (Mb) and can be traced to early vertebrate evolution. Ngb and Cygb display the classical three-on-three -helical globin fold and are endowed with a hexa-coordinate heme Fe atom, in both their ferrous and ferric forms, having the heme distal HisE7 residue as the endogenous sixth ligand. Reversible intramolecular hexa- to penta-coordination of the h…

Activation and translocation of p38 mitogen-activated protein kinase after stimulation of monocytes with contact sensitizers.

2002

Recently we described the induction of tyrosine phosphorylation by contact sensitizers as an early molecular event during the activation of antigen- presenting cells. In this study, the role of the p38 mitogen-activated protein kinase for the activation of human monocytes after exposure to four structurally unrelated contact sensitizers was analyzed in comparison with the irritant benzalkonium chloride and an inductor of oxidative stress (H 2 O 2 ) using immunofluorescence, Western blotting, and enzyme-linked immunosorbent assay techniques. Bio chemical analysis revealed a translocation of p38 from the cytoplasm to the detergent-resistant cell fraction only upon stimulation with contact sen…

A novel regulatory mechanism of MAP kinases activation and nuclear translocation mediated by PKA and the PTP-SL tyrosine phosphatase

1999

Protein tyrosine phosphatase PTP-SL retains mitogen-activated protein (MAP) kinases in the cytoplasm in an inactive form by association through a kinase interaction motif (KIM) and tyrosine dephosphorylation. The related tyrosine phosphatases PTP-SL and STEP were phosphorylated by the cAMP-dependent protein kinase A (PKA). The PKA phosphorylation site on PTP-SL was identified as the Ser231 residue, located within the KIM. Upon phosphorylation of Ser231, PTP-SL binding and tyrosine dephosphorylation of the MAP kinases extracellular signal–regulated kinase (ERK)1/2 and p38α were impaired. Furthermore, treatment of COS-7 cells with PKA activators, or overexpression of the Cα catalytic subunit …