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Frederic Faouzi Harb

Assistant professor
Life & Earth Sciences department - Section II - Fanar
Speciality: Biology
Specific Speciality: Biophysique
Skills: Molecular Biology, Protein Chemistry, Biophysics, Microscopy, Western Blotting, PCR, Biotechnology, Protein Purification, Scientific Writing, Electrophoresis, Fluorescence Microscopy, Spectroscopy, Biochemistry, Cell Culture, Immunohistochemistry, DNA, Immunofluorescence, RT-PCR, Gel Electrophoresis, Fluorescence Recovery After Patterned Photobleaching, Langmuir deposition

Positions
- present : Visiting Professor

Centre Interdisciplinaire de Nanosciences de Marseille
Marseille

Teaching 15 Taught Courses
(2015-2016) B1102 - Génétique, anatomie

BS CSVT (C: Chemistry, Biochemistry, SVT: Life Science and Earth, Geology)

(2015-2016) B1102 - Génétique, anatomie

BS CSVT (C: Chemistry, Biochemistry, SVT: Life Science and Earth, Geology)

(2015-2016) Chim 223 - Thermodynamics of solutions and phase diagrams

BS Chemistry

(2015-2016) Chim 243 - Thermodynamics Lab

BS Chemistry

(2015-2016) Chim 243 - Thermodynamics Lab

BS Chemistry

(2015-2016) Chim 243 - Thermodynamics Lab

BS Chemistry

(2015-2016) Biol 334 - Biophysics

BS Earth and life sciences

(2015-2016) Biol 354 - Biophysics Lab

BS Earth and life sciences

(2014-2015) NSCC 506 - Brain exploration and therapy technics

M2 Behavioral and Cognitive Neurosciences

(2014-2015) Chim 223 - Thermodynamics of solutions and phase diagrams

BS Chemistry

(2014-2015) Chim 243 - Thermodynamics Lab

BS Chemistry

(2014-2015) Chim 243 - Thermodynamics Lab

BS Chemistry

(2014-2015) Chim 280 - General chemistry and organic chemistry Lab

BS Earth and life sciences

(2014-2015) Biol 334 - Biophysics

BS Earth and life sciences

(2014-2015) Biol 354 - Biophysics Lab

BS Earth and life sciences

Education
2009 - 2012: PhD

Aix-Marseille University
Biophysics

Très Honorable avec félicitation du Jury

2008 - 2009: Master

Pierre and Marie Curie University (Paris VI)
Biologie Moléculaire et Biologie de l'Evolution

Très Bien

2004 - 2008: Maitrise ES Sciences

Lebanese University
Biochimie

Bien

Publications 7 publications
Frédéric Harb, Marianne Guiral, Marie-Thérèse Guidici-Orticoni, Bernard Tinland Insertion and self-diffusion of Monotopic Protein, the Aquifex aeolicus Sulfide Quinone Reductase, in supported lipid bilayers The European Physical Journal E 2015

Monotopic proteins constitute a class of membrane proteins that bind tightly to cell membranes, but do not span them. We present a FRAPP (Fluorescence Recovery After Patterned Photobleaching) study of the dynamics of a bacterial monotopic protein, SQR (sulfide quinone oxidoreductase) from the thermophilic bacteria Aquifex aeolicus, inserted into two different types of lipid bilayers (EggPC: L-α-phosphatidylcholine (Egg, Chicken) and DMPC: 1,2-dimyristoyl-sn-glycero-3-phosphocholine) supported on two different types of support (mica or glass). It sheds light on the behavior of a monotopic protein inside the bilayer. The insertion of SQR is more efficient when the bilayer is in the fluid phase than in the gel phase. We observed diffusion of the protein, with no immobile fraction, and deduced from the diffusion coefficient measurements that the resulting inserted object is the same whatever the incubation conditions, i.e. homogeneous in terms of oligomerization state. As expected, the diffusion coefficient of the SQR is smaller in the gel phase than in the fluid phase. In the supported lipid bilayer, the diffusion coefficient of the SQR is smaller than the diffusion coefficient of phospholipids in both gel and fluid phase. SQR shows a diffusion behavior different from the transmembrane protein α-hemolysin, and consistent with its monotopic character. Preliminary experiments in the presence of the substrate of SQR, DecylUbiquinone, an analogue of quinone, component of transmembrane electrons transport systems of eukaryotic and prokaryotic organisms, have been carried out. Finally, we studied the behavior of SQR, in terms of insertion and diffusion, in bilayers formed with lipids from Aquifex aeolicus. All the conclusions that we have found in the biomimetic systems applied to the biological system.

Munteanu Bogdan, Frederic Harb, Jean-Paul Rieu, Yves Berthier,Tinland Bernard, Anna-Maria Trunfio-Sfarghiu Charged particles interacting with a mixed supported lipid bilayer as a biomimetic pulmonary surfactant European Journal of Physics E 2014

This study shows the interactions of charged particles with mixed supported lipid bilayers (SLB) as biomimetic pulmonary surfactants. We tested two types of charged particles: positively charged and negatively charged particles. Two parameters were measured: adsorption density of particles on the SLB and the diffusion coefficient of lipids by FRAPP techniques as a measure of interaction strength between particles and lipids. We found that positively charged particles do not adsorb on the bilayer, probably due to the electrostatic repulsion between positively charged parts of the lipid head and the positive groups on the particle surface, therefore no variation in diffusion coefficient of lipid molecules was observed. On the contrary, the negatively charged particles, driven by electrostatic interactions are adsorbed onto the supported bilayer. The adsorption of negatively charged particles increases with the zeta-potential of the particle. Consecutively, the diffusion coefficient of lipids is reduced probably due to binding onto the lipid heads which slows down their Brownian motion. The results are directly relevant for understanding the interactions of particulate matter with pulmonary structures which could lead to pulmonary surfactant inhibition or deficiency causing severe respiratory distress or pathologies.

Harb Frédéric, Tinland Bernard Effect of Ionic Strength on Dynamics of Supported Phosphatidylcholine Lipid Bilayer Revealed by FRAPP and Langmuir–Blodgett Transfer Ratios Langmuir 2013

To determine how lipid bilayer/support interactions are affected by ionic strength, we carried out lipid diffusion coefficient measurements by fluorescence recovery after patterned photobleaching (FRAPP) and transfer ratio measurements using a Langmuir balance on supported bilayers of phosphatidylcholine lipids. The main effect of increasing ionic strength is shown to be enhanced diffusion of the lipids due to a decrease in the electrostatic interaction between the bilayer and the support. We experimentally confirm that the two main parameters governing bilayer behavior are electrostatic interaction and bilayer/support distance. Both these parameters can therefore be used to vary the potential that acts on the bilayer. Additionally, our findings show that FRAPP is an extremely sensitive tool to study interaction effects: here, variations in diffusion coefficient as well as the presence or absence of leaflet decoupling.

Harb Frédéric, Tinland Bernard Electric migration of a-Hemolysin in supported n-bilayers: a model for transmembrane protein microelectrophoresis Electrophoresis 2013

Proteome analysis involves separating proteins as a preliminary step towards their characterization. This paper reports on the translational migration of a model transmembrane protein (α-Hemolysin) in supported n-bilayers (n, the number of bilayers, varies from 1 to around 500 bilayers) when an electric field parallel to the membrane plane is applied. The migration changes in direction as the charge on the protein changes its sign. Its electrophoretic mobility is shown to depend on size and charge. The electrophoretic mobility varies as 1/R2, with R the equivalent geometric radius of the embedded part of the protein. Measuring mobilities at differing pH in our system enables us to determine the isoelectric point and the charge of the protein. Establishing all these variations points to the feasibility of electrophoretic transport of a charged object in this medium and is a first step toward electrophoretic separation of membrane proteins in n-bilayer systems.

Harb Frédéric, Simon Anne, Tinland Bernard Ripple formation in unilamellar-supported lipid bilayer revealed by FRAPP European Physical Journal E 2013

The mechanisms of formation and conditions of the existence of the ripple phase are fundamental thermodynamic questions with practical implications for medicine and pharmaceuticals. We reveal a new case of ripple formation occurring in unilamellar-supported bilayers in water, which results solely from the bilayer/support interaction, without using lipid mixtures or specific ions. This ripple phase is detected by FRAPP using diffusion coefficient measurements as a function of temperature: a diffusivity plateau is observed. It occurs in the same temperature range where ripple phase existence has been observed using other methods. When AFM experiments are performed in the appropriate temperature range the ripple phase is confirmed.

Harb Frédéric, Sarkis Joe, Ferte Nathalie, Tinland Bernard Beyond Saffman-Delbruck approximation: A new regime for 2D diffusion of α-hemolysin complexes in supported lipid bilayer European Physical Journal E 2012

Cell mechanisms are actively modulated by membrane dynamics. We studied the dynamics of a first-stage biomimetic system by Fluorescence Recovery After Patterned Photobleaching. Using this simple biomimetic system, constituted by α -hemolysin from Staphylococcus aureus inserted as single heptameric pore or complexes of pores in a glass-supported DMPC bilayer, we observed true diffusion behavior, with no immobile fraction. We find two situations: i) when incubation is shorter than 15 hours, the protein inserts as a heptameric pore and diffuses roughly three times more slowly than its host lipid bilayer; ii) incubation longer than 15 hours leads to the formation of larger complexes which diffuse more slowly. Our results indicate that, while the Saffman-Delbruck model adequately describes the diffusion coefficient D for small radii, D of the objects decreases as 1/R 2 for the size range explored in this study. Additionally, in the presence of inserted proteins, the gel-to-fluid transition of the supported bilayer as well as a temperature shift in the gel-to-fluid transition are observed.

Frederic Harb, Mohea Couturier, Laure Decamps, Dorian Guetta, Birgit Habenstein, Elodie Herault, Vincent Kerviel, Nolwen Le Breton, Rachid Menouni, Gilles Phan, Anne-Sophie Tillault CONGRÈS SFBBM – SFB 2012 À GRENOBLE Regard sur la Biochimie 2012

C’est à Grenoble en Isère que s’est tenu le congrès joint de la SFBBM et de la SFB pour l’année 2012. Il s’est déroulé du 21 au 23 Novembre 2012 et s’intitulait : « Mécanismes moléculaires et processus vitaux intégrés ». Douze sessions thématiques, des tables-rondes et une session spéciale "jeunes chercheurs" ont permis de traiter différents aspects alliant la biochimie et la biophysique, allant de la dynamique des génomes et protéomes jusqu’à la biophysique moléculaire et cellulaire. Cette édition 2012 fut marquée par la présence de deux invités de prestige : Jules HOFFMANN et Ernst BAMBERG. Ils nous ont impressionnés par leurs recherches respectives en immunologie, en dévoilant les mécanismes des réponses immunitaires innées et la relation avec les réponses immunitaires adaptatives sur la base du modèle de la drosophile, et en optogénétique, en démontrant par exemple le contrôle de la mobilité d'un nématode génétiquement modifié via des canaux d’ions sensibles à la lumière.

Supervision 4 Supervised Students
Fabrication of a 1W power Laser

Nahed Rudy
This intership was conducted to a student in his second year of master's at the Lebanese University- Section II in the purpose of understanding the processus of fabricating a high power Laser.

Initiation au travail d'un scientifique

Bertille Castel
Ce stage a été conduit pour une étudiante en première année de licence à l'université d'Aix-Marseille afin de comprendre et d'apprendre le travail d'un chercheur au sein de son laboratoire.

Role of renewable energy sources in environmental protection

Kawsar Saad

Renewable technologies are considered as clean sources of energy. Their optimal use minimizes environmental impacts, produce minimum secondary wastes and are sustainable based on current and future economic and social societal needs. The primary forms of solar energy are heat and light. Sunlight and heat are transformed and absorbed by the environment in a multitude of ways. Some of these transformations result in renewable energy flows such as biomass and wind energy. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In this report are view has been done on scope of CO2 mitigation through solar cooker, water heater, dryer, biofuel, improved cookstoves and by hydrogen.

Comprehensive review of renewable energy curtailment and avoidance

Zahraa Al Moussawi

In order to ensure healthy air and a stable climate we must make responsible decisions about our energy sources. Existing technologies and forward-thinking policies offer practical and affordable solutions to reduce our dependence on the fossil fuels that currently dominate world’s electricity system. This system threatens the health of our communities by polluting the air and contributing to global warming. Practical solutions do exist. For example, many countries have adopted a renewable electricity standard-a policy that requires electricity suppliers to gradually increase their use of renewable energy such as wind, solar, geothermal, and bioenergy. Carbon Capture and Storage (CCS) is a technology that can capture up to 90% of the carbon dioxide (CO2) emissions pro¬duced from the use of fossil fuels in electricity generation and industrial processes, preventing the carbon dioxide from entering the atmosphere. The global installed renewable energy capacity booms, but many problems regarding grid integration appears due to the variability and uncertainty in the output of renewable energy generation. Therefore, large amount of curtailed electric energy (CEE) exists, which means some of the renewable energy generation must be wasted to keep real-time balance between load and generation in power system. In this thesis, the CEE is defined and the main causes for CEE are discussed. Then, the worldwide CEE is estimated; moreover, to evaluate the utilization priority of various generation resources, the potential of reducing fossil fuel consumption, greenhouse gas (GHG) emissions and air pollutants as well as the potential of capturing CO2 with CEE are analyzed. Possible CEE reduction strategies are also presented. Key words: renewable energy, CCS, CEE, GHG, power generation.

Languages
Arabic

Full professional proficiency

English

Full professional proficiency

French

Full professional proficiency

Spanish

Elementary proficiency