Publications associées à Hème

Publications associées (21)

Ultrafast X-ray Spectroscopy of Haem Proteins

Majed Chergui, Camila Bacellar Cases Da Silveira

In this article we revisit our recent picosecond and femtosecond X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) experiments, probing the ultrafast electronic and geometric evolution of photoexcited haem proteins, namely ferrous N ...

SWISS CHEMICAL SOC2022

Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies

Majed Chergui, Wojciech Gawelda, Giulia Fulvia Mancini, Christopher Alexander Arrell, Frederico Alves Lima, Oliviero Cannelli, Dominik Kinschel, Camila Bacellar Cases Da Silveira, Jérémy Raymond Jean Maurice Rouxel, Rebecca Ann Ingle

The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (C ...

National Academy of Sciences2020

Effect of Single-Point Mutations on Nitric Oxide Rebinding and the Thermodynamic Stability of Myoglobin

Polydefkis Diamantis

The effect of single amino acid mutations on the rebinding dynamics of nitrogen monoxide (NO) to myoglobin is investigated using reactive molecular dynamics simulations. In particular, mutations of residues surrounding the heme-active site (Leu29, His64, V ...

AMER CHEMICAL SOC2019

More Medicines for Tuberculosis: Fuelling Drug Discovery against Mycobacterium tuberculosis

Shi-Yan Caroline Foo

Tuberculosis (TB), whose etiological agent is Mycobacterium tuberculosis (M. tuberculosis), has plagued humanity since antiquity. Even with chemotherapy available today, TB is the leading cause of death due to an infectious disease. Modern day factors, suc ...

EPFL2018

Non-invasive continuous monitoring of pro-oxidant effects of engineered nanoparticles on aquatic microorganisms

Olivier Martin, Paul Bowen, Christian Santschi, Volodymyr Koman, Nadia Rachel Von Moos

Engineered nanomaterials (ENMs) are key drivers for the development of highly sophisticated new technologies. As all new attainments, the rapidly increasing used of ENMs raise concerns about their safety for the environment and humans. There is growing evi ...

2017

Photo-induced oxidation of the uniquely liganded heme f in the cytochrome b(6)f complex of oxygenic photosynthesis

Frank van Mourik, Andre Al Haddad, Adrien Alexis Paul Chauvet

The ultrafast behavior of the ferrous heme f from the cytochrome b(6)f complex of oxygenic photosynthesis is revealed by means of transient absorption spectroscopy. Benefiting from the use of microfluidic technologies for handling the sample as well as fro ...

Royal Society of Chemistry2016

Tryptophan-to-heme electron transfer in ferrous myoglobins

Majed Chergui, Frank van Mourik, Gerald Auböck, Andre Al Haddad, Roberto Monni

It was recently demonstrated that in ferric myoglobins (Mb) the fluorescence quenching of the photoexcited tryptophan 14 (*Trp(14)) residue is in part due to an electron transfer to the heme porphyrin (porph), turning it to the ferrous state. However, the ...

National Academy of Sciences2015

Photo-induced dynamics of the heme centers in cytochrome bc(1)

Majed Chergui, Frank van Mourik, Andre Al Haddad, Adrien Alexis Paul Chauvet

The ultrafast response of cytochrome bc1 is investigated for the first time, via transient absorption spectroscopy. The distinct redox potentials of both c(1)- and b-hemes allow for a clear differentiation of their respective signals. We find that while th ...

Royal Society of Chemistry2015

Portable oxidative stress sensor: Dynamic and non-invasive measurements of extracellular H2O2 released by algae

Olivier Martin, Christian Santschi, Volodymyr Koman

Reactive oxygen species (ROS) generated by aerobic organisms are essential for physiological processes such as cell signaling, apoptosis, immune defense and oxidative stress mechanisms. Unbalanced oxidant/antioxidant budgets are involved in many diseases a ...

Elsevier2015

A cascade through spin states in the ultrafast haem relaxation of met-myoglobin

Majed Chergui, Frank van Mourik, Olivier Christian Bräm, Gerald Auböck, Cristina Consani

We report on a study of the early relaxation processes of met-Myoglobin in aqueous solution, using a combination of ultrafast broadband fluorescence detection and transient absorption with a broad UV-visible continuum probe at different pump energies. Reco ...

American Institute of Physics2014

Ultrafast Tryptophan-to-Heme Electron Transfer in Myoglobins Revealed by UV 2D Spectroscopy

Majed Chergui, Frank van Mourik, Gerald Auböck, Cristina Consani

Tryptophan is commonly used to study protein structure and dynamics, such as protein folding, as a donor in fluorescence resonant energy transfer (FRET) studies. By using ultra-broadband ultrafast two-dimensional (2D) spectroscopy in the ultraviolet (UV) a ...

American Association for the Advancement of Science2013

Biliverdin Reductase-A correlates with inducible nitric oxide synthasein in atorvastatin treated aged canine brain

Eugenio Barone

Alzheimer's disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug for Alzheimer's disease, but the exact ...

Shenyang Editorial Dept Neural Regeneration Res2013

Superior sensing performance of multi-walled carbon nanotube-based electrodes to detect unconjugated bilirubin

Giovanni De Micheli, Sandro Carrara, Irene Taurino

The direct electrochemical behaviour of bilirubin in the physio-pathological concentration range and at physio- logical pH was investigated by cyclic voltammetry. Nanostructured electrodes with a thin film of multi-walled carbon nanotubes exhibited a highe ...

Elsevier2013

Sensing the dynamics of oxidative stress using enhanced absorption in protein-loaded random media

Olivier Martin, Christian Santschi, Vera Slaveykova-Startcheva, Guillaume Suarez

Reactive oxygen species play a key role in cell signalling and oxidative stress mechanisms, therefore, sensing their production by living organisms is of fundamental interest. Here we describe a novel biosensing method for extracellular detection of endoge ...

Nature Publishing Group2013

Ligand Discrimination in Myoglobin from Linear-Scaling DFT+U

David Daniel O'Regan

Myoglobin modulates the binding of diatomic molecules to its heme group via hydrogen-bonding and steric interactions with neighboring residues, and is an important benchmark for computational studies of biomolecules. We have performed calculations on the h ...

2012

Biophotonic tool for sensing the dynamics of H2O2 extracellular release in stressed cells

Olivier Martin, Christian Santschi, Shourya Dutta Gupta

Hydrogen peroxide (H2O2) is known to play a multifaceted role in cell physiology mechanisms involving oxidative stress and intracellular signal transduction. Therefore, the development of analytical tools providing information on the dynamics of H2O2 gener ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2012

Ablation of the Tumor Suppressor Histidine Triad Nucleotide Binding Protein 1 is Protective Against Hepatic Ischemia/Reperfusion Injury

The identification of cellular pathways capable of limiting ischemia/reperfusion (I/R) injury remains a frontier in medicine, and its clinical relevance is urgent. Histidine triad nucleotide binding protein 1 (HINT1) is a tumor suppressor that influences a ...

2011

RETRACTED: On the enzymatic activity of catalase: an iron L-edge X-ray absorption study of the active centre

Majed Chergui

Catalase and methaemoglobin have very similar haem groups, which are both ferric, yet catalase decomposes hydrogen peroxide to water and oxygen very efficiently, while methaemoglobin does not. Structural studies have attributed this behaviour to their diff ...

Royal Society of Chemistry2010

Electrocatalysis at liquid/liquid interfaces

This thesis is devoted to the study of oxygen reduction reaction catalysed by porphyrins at the interface between two immiscible electrolyte solutions (ITIES). Electrochemical and spectrophotometric techniques are introduced to these interfaces in order to ...

EPFL2010

Characterization of active site structure in CYP121: A cytochrome P450 essential for viability of Mycobacterium tuberculosis H37Rv

Stewart Cole

Mycobacterium tuberculosis (Mtb) cytochrome P450 gene CYP121 is shown to be essential for viability of the bacterium in vitro by gene knock-out with complementation. Production of CYP121 protein in Mtb cells is demonstrated. Minimum inhibitory concentratio ...

2008