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SALMAIN Michèle
Directrice de Recherche CNRS, HDR

Sorbonne Université,
4 Place Jussieu, 75252 Paris cedex 5

Couloir 33-43 4ème étage. case 229
Team Chembio


Tel:33(0)1 44 27 67 32

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Research interests: 


Protein chemistry, bioorganometallic chemistry, bioanalysis.

Current research:

  • Theme 1 : Organometallic chemistry on proteins – design of artificial metalloenzymes
  • Theme 2 : Design of immunosensors for food and environmental analysis

Recent results:

  • Theme 1 : artificial metalloenzymes

It is undeniable that the most important breakthrough of transition metal coordination chemistry (even at the industrial level) lies in the area of homogeneous catalysis. In parallel, enzymes are increasingly employed for the synthesis of chiral compounds. At the border between these 2 domains, an original concept coined « artificial metalloenzymes » has recently emerged in which biomacromolecules (proteins, DNA) serve as hosts for metallic species.

In this field, we have designed and prepared artificial metalloproteins resulting from the anchoring of half-sandwich diimine Ru(II) and Rh(III) complexes to papain as protein host. This protein is a cysteine endoproteinase including a single free cysteine residue (C25) within its catalytic site. The designed organometallic complexes display a chloroacetamide, maleimide or methylthiosulfonate reactive function on the arene or the diimine ligand allowing their site-specific anchoring to papain.

Hybrid metalloproteins displayed a cofactor : protein ratio of 1 :1. Full loss of the proteolytic activity of the hybrids confirmed that anchoring occurred via the reaction of Cys25. We showed that modified papain acquired new catalytic properties. In particular, one of the artificial metalloproteins catalyzed the Diels-Alder reaction between cyclopentadiene and acrolein in water at 4°C with a TOF of 220 h-1 versus 1.4 h-1 for the metallic complex alone. Other hybrid metalloproteins catalyzed the reduction of NAD(P)+ to NAD(P)H by hydrogen transfer. The most active metallopapains catalyzed the conversion of NAD+ with a TOF of ca. 50 h-1. They were also able to catalyze the hydrogenation of trifluoroacetophenone by hydrogene transfer in the presence of formate with an enatiomeric excess of 15% (R).

In the frame of the research programme ARTZYMES funded by the ANR (2011-2014), we initiated investigations on the use of bovine beta-lactoglobulin (bLG) as protein host. bLG is a protein belonging to the superfamily of lipocalins that is very abundant in the whey fraction of cow’s milk. Its 3D structure consists of a anti-parallel, 8-stranded beta-barrel. bLG displays high affinity for hydrophobic ligands as fatty acids that occupy the central cavity of the protein. Given these structural properties, we thought that bLG could be appropriate for the formation of artificial metalloenzymes by the supramolecular anchoring strategy. Half-sandwich diimine Ru(II) and Rh(III) complexes derived from saturated and unsaturated fatty acids were synthesized. Complexation of some of these complexes to bLG was demonstrated by CD and fluorescence spectroscopy and confirmed by X-ray crystallographic studies. The transfer hydrogenase activity of the artificial metalloenzymes was measured on the benchmark substrate trifluoroacetophenone. The most selective hybrid species was the one resulting from the association of the Rh(III) cofactor derived from stearic acid with enantiomeric excess reaching 32% (R).

  • Theme 2 : Immunosensors for the analysis of toxins
    In the frame of the research programme « BIOCAPTOX » funded by the ANR (2007 – 2011), we became involved in the design of an immunosensor for the detection of one of the enterotoxins produced by Staphylococcus aureus, i.e. enterotoxin A (SEA). This toxin is most frequently involved in food poisoning outbreaks by S. aureus. In its simplest configuration, an immunosensor consists of a bioreceptor (for instance an antibody) immoblilized on a transducing element (for instance an electrode). Capture of the target analyte by the recognition layer results in a measurable physical signal. We chose a piezoelectric (acoustic) detection mode measured by a quartz crystal microbalance (QCM) since this technique allows to measure variations of mass in the order of the ng at the surface of a piezoelectric quartz crystal in solution and in real time. A self-assembled monolayer of cystamine was first formed at the surface of the gold electrode covering the quartz crystal followed by activation of the amine groups by phenylene diisothiocyanate. Formation of the recognition layer made of protein A and polyclonal anti-SEA antibody then capture of target SEA was monitored in real time by the resonance frequency. A correlation was established between the frequency variation delta-F and the quantity of SEA in the range between 5 and 500 ng. We also demonstrated that this immunosensor could also detected SEA in spiked milk without extraction step.

Scientific career

  • 1987 : Engineer graduated from the Ecole Nationale Superieure de Chimie de Paris
  • 1987 : DEA in organic chemistry of the Université Pierre et Marie Curie
  • 1990 : Ph. D. thesis in organic chemistry, Université Pierre et Marie Curie under the supervision of Professor Gerard Jaouen. Title of the thesis : synthesis of metal carbonyl derivatives of pharmaceutical drugs ; application to the immunological assay of haptens bu Fourier transforrn infrared
  • 2001 : Price of the coordination chemistry division of the French chemical society
  • 2005 : Habilitation delivered by the Université Pierre et Marie Curie
  • 1991 : Post-doctoral studies financed by CNRS and Medgenx company
  • 1992 – 2008 : chargée de recherche CNRS
  • depuis 2008 : directrice de recherche CNRS

Selected publications:

  1. P. Haquette, B. Dumat, B. Talbi, S. Arbabi, J.-L. Renaud, G. Jaouen, and M. Salmain. (2009) Synthesis of N-functionalized 2,2’-dipyridylamine ligands, complexation to ruthenium(II) and anchoring of complexes to papain from papaya latex, J. Organomet. Chem. 694, 937-941.
  2. N. Fischer-Durand, M. Salmain, B. Rudolf, L. Dai, L. Jugé, V. Guérineau, O. Laprévote, A. Vessières, and G. Jaouen. (2010) Site-Specific Conjugation of Metal-Carbonyl Dendrimer to Antibody and its Use as Detection Reagent in Immunoassay, Anal. Biochem. 407, 211-219.
  3. B. Talbi, P. Haquette, A. Martel, F. de Montigny, C. Fosse, S. Cordier, T. Roisnel, G. Jaouen, and M. Salmain. (2010) (η6-arene) ruthenium(II) complexes and metallo-papain hybrid as Lewis acid catalysts of Diels-Alder reaction in water, Dalton Trans. 39, 5605-5607.
  4. P. Haquette, B. Talbi, L. Barilleau, N. Madern, C. Fosse, and M. Salmain. (2011) Chemically engineered papain as artificial formate dehydrogenase for NAD(P)H regeneration, Org. Biomol. Chem. 9, 5720 - 5727.
  5. M. Salmain, M. Ghasemi, S. Boujday, J. Spadavecchia, C. Técher, F. Val, V. Le Moigne, M. Gautier, R. Briandet, and C.-M. Pradier. (2011) Piezoelectric immunosensor for direct and real-time detection of staphylococcal enterotoxin A (SEA) at the ng level, Biosens. Bioelectron. 29, 140-144.
  6. A. Chevalley, and M. Salmain. (2012) Enantioselective transfer hydrogenation of ketone catalysed by artificial metalloenzymes derived from bovine b-lactoglobulin, Chem. Commun. 48, 11984-11986.
  7. M. Salmain, M. Ghasemi, S. Boujday, and C.-M. Pradier. (2012) A quartz crystal microbalance biosensor for the detection of staphylococcal enterotoxin A (SEA) in milk samples, Sens. Actuators B 173, 148-156.
  8. M. V. Cherrier, S. Engilberge, P. Amara, A. Chevalley, M. Salmain, and J. C. Fontecilla-Camps. (2013) Structural basis for enantioselectivity in the transfer hydrogenation of a ketone catalyzed by an artificial metalloenzyme, Eur. J. Inorg. Chem., 3596-3600.
  9. B. Rudolf, M. Salmain, J. Grobelny, G. Celichowski, and M. Cichomski. (2013) Preparation of metallocarbonyl-gold antibody bioconjugates for mid-IR optical immunosensing, J. Organomet. Chem. 734, 32-37.
  10. A. Chevalley, M. V. Cherrier, J. C. Fontecilla-Camps, M. Ghasemi, and M. Salmain. (2014) Artificial metalloenzymes derived from bovine β-lactoglobulin for the asymmetric transfer hydrogenation of an aryl ketone – synthesis, characterization and catalytic activity, Dalton Trans. 43, 5482 - 5489.