Publications associées à Hème a

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

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

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, Rachna Agarwal

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, Andre Al Haddad, Gerald Auböck, 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

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

Christian Santschi, Olivier Martin, 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

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

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

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

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

Ligand Discrimination in Myoglobin from Linear-Scaling DFT+U

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

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

Probing the Electronic Structure of the Hemoglobin Active Center in Physiological Solutions

Majed Chergui

Soft-x-ray absorption spectroscopy at the L2,3 edge of the iron center in bovine Hb and hemin under physiol. conditions is reported for the first time. Spectra of the same compds. in solid form are presented for comparison. Striking differences in the elec ...

2009