01.04.2014, 17:00

Prof. Dr. Francois Lépine "Quorum sensing: A new pathway for the synthesis of 4-hydroxy-2-alkylquinolines, the signaling molecules of Pseudomonas aeruginosa"



Pseudomonas areuginosa is an ubiquitous Gram negative bacterium. It is also an opportunistic human pathogen which is responsible for many nosocomial infections, especially for patients with immunodeficiencies. It is also the main factor of mortality for patients with cystic fibrosis. This bacterium possesses a vast array of virulence factors, many of which are under the control of quorum sensing. In P. aeruginosa, there are three such quorum sensing systems, one of which is the PQS system (for Pseudomonas Quinolone System). The signaling compounds of the PQS system belong to a family of 4-hydroxy-2-alkylquinolines (HAQ). As we previously shown that inhibiting the biosynthesis of HAQ lead to a decrease of the virulene of the bacteria, we got interested in the biosynthesis of these compounds in an effort to find molecules that could inhibit their production. Although the genes responsible for the production of HAQ have been identified, the role of many of the proteins they encoded had not been determined. In this presentation we will present our findings on the role of these enzymes and the nature of the intermediates that are incorporated into HAQ.


Prof. Lépine studied Chemistry at the Université du Québec à Montréal (B.Sc. in Biochemistry and M.Sc in Organic Chemistry) and obtained his PhD in Organic Chemistry at the McGill University, Montreal with Dr B. Belleau in 1985. He worked as a research assistant at the Biomedical Mass Spectrometry Unit at McGill University with Dr. O.A. Mamer and became Professor at the INRS-Institut Armand-Frappier, Laval, Université du Québec in 1987.
Prof. Lépine is the author of 131 peer review publications in such fields as mass spectrometry, environmental bioremediation, enzymology, biochemistry and microbiology.
His more recent research interests are in the analytical chemistry of microbial metabolites such as rhamnolipids, siderophores and signaling molecules produced by various bacteria. I am especially interested in the biosynthesis of 4-hydroxy-2-alkylquinolines (HAQ), which are signaling compounds of the opportunistic pathogen Pseudomonas aeruginosa, in an effort to understand their biosynthesis, as inhibition of HAQ production lead to a decrease of the virulence of these bacteria.


01.04.2014, 17:00


Universität des Saarlandes

Building and room

in Blg C4 3,
Kleiner Hörsaal der Anorganischen Chemie


Francois Lépine
INRS-Institut Armand-Frappier,
Laval Université du Québec


Rolf Hartmann

How to find us in Saarbrücken 

The HIPS building is located at the east entrance on the main campus of Saarland University, which is situated outside the city centre of Saarbrücken, the state capital of Saarland. Saarland is located in the south-west of Germany, having common frontiers with Luxembourg and France.


Helmholtz-Institut für Pharmazeutische Forschung Saarland (HIPS)
Universitätscampus E8 1
66123 Saarbrücken

By car

  • from the north (Cologne/Trier) via the motorway A1/A8 to „Autobahnkreuz Neunkirchen“, take A6 to „Saarbrücken“
  • from the east (Kaiserslautern/Mannheim) via A6 to "Saarbrücken/Paris"
  • from the north-west from Luxembourg via A620 by-pass the city centre and follow A6 to „Mannheim“
  • from the west (Metz/Paris) and south-west (Strasbourg) via the A4/A320 (E50) follow A6 (E50) to „Mannheim“
  • to reach the campus from motorway A6: take exit no. 5 „St. Ingbert West/Universität“, follow „Universität Ost“, (ca. 6 km)

By train

(ICE/TGV and Intercity - Saarbrücken Central Station) you can reach the campus by local busses from the main train station (112, 124) and the city centre (101, 102, 109, 111) within 15 min 
(see www.bahn.de)



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