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Targeting the cell envelope

The knowledge acquired on the MA metabolic pathway have brought precious tools for targeting the mycobacterial cell envelope. Thus, we reinforced our expertise and tightened collaborations for the functional characterization of biological targets (genetics, biochemistry, enzymology, biophysics, structural biology), which resulted in a better understanding of the involved molecular mechanisms. Our group has also been involved in collaborations with pharmaceutical groups for drug screening on several of our targets.


In this context, we deposited a patent for the use of the FAS-II dehydratases as therapeutic targets. Furthermore, we contributed to demonstrate that HadAB is the primary target of the antituberculous prodrugs thiacetazone and isoxyl, which covalently bind to HadA, likely blocking access of the fatty acyl substrate to its binding channel. 


The inhibition mechanisms of the activity of the fatty acyl-AMP/ACP ligase FadD32 by alkyl adenylates were analyzed through crystallography of FadD32 orthologs in complex with alkyl-AMP inhibitors. Being successful in adapting enzyme assays to microplate format with the aim of HTS campaigns, we screened a library of well-known drugs used in the treatment of different diseases other than tuberculosis and identified several inhibitors of both FadD32 activity and Mtu growth of. We thus define a pharmacophore for further development of more efficient inhibitors. 
 

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Current collaborators

  • Odile Schiltz's group, Institut de Pharmacologie et Biologie Structurale, Toulouse
  • Lionel Mourey's group, Institut de Pharmacologie et Biologie Structurale, Toulouse
  • Plateforme PICT, Institut de Pharmacologie et Biologie Structurale, Toulouse
  • Pierre Verhaeghe, Laboratoire de Chimie de Coordination, Toulouse
  • Mary Jackson's group, Colorado State University, Fort-Collins (USA)
  • Matthias Wilmanns, EMBL, Hamburg (Germany)
  • Przemyslaw Plocinski, Institute of Medical Biology, Lodz (Poland)

 

Selected publications

  • Daffé M, Quémard A & Marrakchi H (2017) Mycolic acids: from Chemistry to Biology. In Biogenesis of Fatty Acids, Lipids and Membranes, O Geiger ed, Handbook of Hydrocarbon and Lipid Microbiology series (Springer, Cham), ISBN 978-3-319-43676-0
  • Guillet V et al (2016) Insight into Structure-Function Relationships and Inhibition of the Fatty Acyl-AMP Ligase (FadD32) Orthologs from Mycobacteria. J Biol Chem 291:7973-89
  • Slama N et al (2016) The changes in mycolic acid structures caused by hadC mutation have a dramatic effect on virulence of Mycobacterium tuberculosis. Mol Microbiol 99:794-807
  • Grzegorzewicz AE et al (2015) Covalent modification of the Mycobacterium tuberculosis FAS-II dehydratase by Isoxyl and Thiacetazone. ACS Infect Dis 1:91-7
  • Galandrin, S., Guillet, V., Rane, R., Léger, M., Radha, N., Eynard, N., Das, K., Balganesh, T., Mourey, L. Daffé, M. and Marrakchi, H. (2013) Assay development for identifying inhibitors of the mycobacterial FadD32 activity. J. Biomol. Screening 18: 576-87
  • Grzegorzewicz AE et al (2012) A common mechanism of inhibition of the Mycobacterium tuberculosis mycolic acid biosynthetic pathway by isoxyl and thiacetazone. J Biol Chem 287:38434-41.
  • Vaubourgeix J et al (2009) SADAE, a potent bisubstrate inhibitor of mycolic acid methyltransferase of Mycobacterium tuberculosis. J Biol Chem 284:19321-19330 

 

Patents

  • Bardou F., Boulon R., Bousquet M.P., Burlet-Schiltz O., Daffé M., Ducoux-Petit M., Eynard N., Gavalda S., Lefebvre C. & Quémard A. "HadD, a novel protein of the mycobacterial fatty acid synthase type II". Deposited on August 3rd, 2017 at the European Patent Office, under # EP17306041.9.
  • Quémard A., Daffé M., Sacco E., Jones T.A., Bäckbro K., Suarez Covarrubias A. "(3R)-hydroxyacyl-ACP dehydratase enzymes involved in mycolic acid biosynthesis and their use for antibiotic screening". Deposited on February 9th, 2007 at INPI, under # FR07 00930 (Publication # FR2912422).
  • Guilhot C, Daffé M, Houssin C, Portevin D, De Sousa C. "Use of Pks13 protein coding for condensase of mycolic acids of mycobacteria and related strains as an antibiotics target". Deposited on September 4th, 2003 at INPI, under # FR20030010470.