«Green chemistry, from synthetic catalysts to artificial and natural enzymes»

The workshop will consist of 5 invited lectures, and 6 selected talks.

The workshop is organized at IMéRA (Institute for Advanced Study of Aix-Marseille University) as part of the residence of the scientific team that includes Jochen Blumberger, Luca de Gioia, Claudio Greco and Philippe Schollhammer.

Program:

9h Welcome
9h15 Opening
9h30 Jochen Blumberger
10h Claudio Greco
10h30 Carole Baffert
11h Break
11h15 Philippe Schollhammer
11h45 Marina Siponen
12h15 Lunch
14h Marius Réglier
14h30 Pierre Rousselot Pailley
15h Aurélien de la Lande
15h30 Break
16h Ling Peng
16h30 Pierre Ceccaldi
17h Stéphane Ménage

* = selected from submitted abstracts

Location and access



Registration





Abstracts:

9h15 Opening words

9h30 Jochen Blumberger (invited)
University College London, Department of Physics and Astronomy
"A multiscale computational model for small ligand diffusion within proteins with applications to hydrogenase and carbon monoxide dehyrogenase"

We describe a general microscopic model for the calculation of diffusion and binding rates of small ligands (e.g. gas molecules) to protein active sites [1-3]. In our model, the diffusive hopping of the ligand within the protein is coarse grained using a master equation approach with transition rates between the coarse states (= protein cavities) estimated from equilibrium and non-equilibrium molecular dynamics simulations and density functional theory for the final chemical binding step. The master equation is propagated to obtain the ligand population of the active site as a function of time. A fit of the time-dependent populations to a phenomenological rate law gives the phenomenological diffusion rate constants that can be compared to experimental measurements. We report the application of this methodology to a number of enzymes that have recently attracted much interest for biotechnological applications such as H2 oxidation and production in biofuel cells ([NiFe]-hydrogenase) [1,2] as well as CO2 reduction and production of biomass (Carbon-monoxide dehydrogenase/Acetyl co-enzyme A synthase (CODH/ACS)) [3]. We find that experimentally determined diffusion rates of inhibitors in wild-type [1] and mutant [2] hydrogenases can be well reproduced with our method. Moreover, our simulations can explain how mutations impact on inhibitor diffusion [2]. We will show that this method can give unprecedented insight into the structural features that are built into enzymes to guide the flow of ligands into and between active sites [3]. We will also demonstrate that incorporation of protein dynamical effects is crucial for a more complete understanding of how small ligands travel from the solvent to enzyme active sites. [1] P. Wang, R. B. Best, J. Blumberger, J. Am. Chem. Soc. 133, 3548 (2011). [2] P. Wang, J. Blumberger, Proc. Natl. Acad. Sci. USA , 109, 6399 (2012). [3] P. Wang, M Bruschi, L. De Gioia, J. Blumberger, J. Am. Chem. Soc. 135, 9493 (2013).


10hClaudio Greco,a*, Maurizio Bruschi,a Luca De Gioia b  (invited)
a Dipartimento di Scienze dell’Ambiente e del Territorio, e di Scienze della Terra, e b Dipartimento di Biotecnologie e Bioscienze; Università di Milano-Bicocca, Piazza della Scienza 1-2, 20126, Milano (Italia)
"Theoretical insights on H2 binding and splitting at [FeFe] and [NiFe] hydrogenase models: a dialogic perspective."


The present contribution will focus on key aspects of substrate-dependent redox chemistry in hydrogenases models, a theme that has been studied in our laboratories by means of quantum mechanical and hybrid quantum/classical (QM/MM) calculations. We developed a QM/MM model of Desulfovibrio desulfuricans [FeFe] hydrogenase (DdH) featuring quantum chemical description of the whole inorganic core (which is composed by the Fe6S6 H-cluster and two ancillary, F and F’ cubane clusters) [1]. Results indicate that the binding of the redox partners of DdH in proximity of its F'-cluster can trigger one-electron oxidation of the H2-bound enzyme, a process that is expected to have an important role in H2 activation. A parallel study devoted to the in silico design of bioinspired catalysts indicated that the installment of ligands derived from common metallocenes on biomimetic diiron cores can lead to the enhancement of functionally relevant intramolecular electron transfers [2], a concept that found experimental support very recently [3]. We also verified the possibility of transferring similar concepts to the case of [NiFe] hydrogenases modeling [4, 5]. Notably, our data support the idea that a unified view on [FeFe] and [NiFe] hydrogenases chemistry is a key element to direct future efforts in the modeling of microbial H2 metabolism [5].
[1] Greco, C.; Bruschi, M.; Fantucci P.; Ryde, U.; De Gioia, L. J. Am. Chem. Soc. 2011, 46, 18742-18749. [2] Greco, C.; De Gioia, L. Inorg. Chem. 2011, 50, 6987-6995. [3] Camara, J. M.; Rauchfuss, T. B. Nat. Chem. 2012, 4, 26-30. [4] Greco, C. Inorg. Chem. 2013, 52, 1901-1908 [5] Greco, C., Dalton Trans. 2013, 42, 13845-13854


10h30Carole Baffert
Carole Baffert1, Vivianne Hajj1, Kateryna Sybirna3, Claudio Greco4, Isabelle Meynial-Salles2, Vincent Fourmond1, Luca De Gioia4, Hervé Bottin3, Philippe Soucaille2, Christophe Léger1
1 Bioenergetics and Engineering of Proteins, UMR7281-FR3479 CNRS/AMU, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
2 Université de Toulouse, INSA, UPS, INP, LISBP, INRA/UMR 792, 135 CNRS/UMR 5504, Avenue de Rangueil, 31077 Toulouse, France
3 iBiTec-S SB2SM, LPB (URA CNRS 2096), DSV, CEA, 91191 Gif-sur-Yvette, France
4 Department of Biotechnology and Biosciences, Universit.a degli Studi di Milano-Bicocca, Milan 20126, Italy
Potential dependence of CO inhibition and low potential inactivation of FeFe hydrogenases

Hydrogenases, the enzymes that oxidize and produce H2, can be covalently attached to electrodes, forming a stable protein films while maintaining direct electron transfer [1].
FeFe hydrogenases are inactivated under various conditions: presence of CO or O2, extreme potentials [2-3]. On one hand, using an original approach, which combines accurate electrochemical measurements and theoretical calculations, we elucidate the mechanism by which, under certain conditions, CO binding can cause permanent damage to the active site (H-cluster)[3]. One another hand, thanks to covalent immobilization of the enzymes, we show that FeFe hydrogenases inactivate at low potential, in a complex process that is mostly reversible. A form of the enzyme that is produced slowly and reversibly under reductive conditions has no proton activity under reductive conditions, although it can still oxidize H2 under oxidative conditions [4].

[1] C. Baffert et al, “Covalent attachment of FeFe hydrogenases to carbon electrodes for direct electron transfer”, Anal. Chem. 2012, 84, 7999 [2] Baffert, C.; Demuez, M.; Cournac, L.; Burlat, B.; Guigliarelli, B.; Bertrand, P.; Girbal, L.; Leger, C. Angew. Chem. Int. Ed. 2008, 47, (11), 2052-2054. [3] Baffert, C.; Bertini, L.; Lautier, T.; Greco, C.; Sybirna, K.; Ezanno, P.; Etienne, E.; Soucaille, P.; Bertrand, P.; Bottin, H.; Meynial-Salles, I.; De Gioia, L.; Leger, C. J. Am. Chem. Soc. 2011, 133, (7), 2096-2099. [4] V Hajj et al,  “Reductive inactivation of FeFe hydrogenase and implication for catalysis” Energy and Environmental Science 7(2) 715-719 (2014)

11h Break

11h15 Philippe Schollhammer  (invited)
UMR CNRS 6521, Chimie, Electrochimie Moléculaires et Chimie Analytique, Faculté des Sciences, Université de Bretagne Occidentale, 6 Avenue Le Gorgeu, C.S. 93837, 29238 Brest cedex 3, France.
Design of electrocatalysts bioinspired by the active site of [Fe-Fe] hydrogenases

Recent results, related to the design of electrocatalysts inspired by the active site of [FeFe] hydrogenases, combining organometallic synthesis, electrochemical investigations and theoretical calculations, will be presented. In particular, the presentation will address strategies to induce a specific conformation of synthetic diiron molecules considered as models of the [2Fe]H subsite, but also for introducing acid-base and redox functionalities through the use of base-relay and non-innocent ligands.

[1] New Fe-I-Fe-I Complex Featuring a Rotated Conformation Related to the [2Fe](H) Subsite of [Fe-Fe] Hydrogenase, S. Munery, J.-F. Capon, L. De Gioia, C. Elleouet, C.Greco, F.-Y. Pétillon, P.Schollhammer, J. Talarmin,  G. Zampella,  Chemistry, A European Journal, 2013, 19, 15458-15461; [2] Electrochemical and theoretical investigations of the role of the appended base on the reduction of protons by [Fe2(CO)4(k2-PNPR)(µ-S(CH2)3S] (PNPR = {Ph2PCH2}2NR, R = Me, Ph) S. Lounissi, G. Zampella, J.-F. Capon, L. De Gioia, F. Matoussi, S. Mafhoudi, F.-Y. Pétillon, P.Schollhammer, J. Talarmin, Chemistry, A European Journal, 2012, 18, 11123-11138. [3] Diiron species containing a cyclic Pph2NPh2 diphosphine related to the [FeFe]H2ases active site, S. Lounissi, J-F. Capon, F. Gloaguen, F. Matoussi, F. Y. Pétillon, P. Schollhammer, J. Talarmin, Chem Commun, 2011, 47, 878-880



11h45Marina Siponen, Legrand P, Widdrat M, Jones SR, Zhang WJ, Chang MC, Faivre D, Arnoux P, Pignol D.
Laboratoire de Bioénergétique Cellulaire (LBC), CEA, Cadarache, F.
"Structural insight into magnetochrome-mediated magnetite biomineralization."

Magnetotactic bacteria align along the Earth's magnetic field using an organelle called the magnetosome, a biomineralized magnetite (Fe(II)Fe(III)2O4) or greigite (Fe(II)Fe(III)2S4) crystal embedded in a lipid vesicle. Although the need for both iron(II) and iron(III) is clear, little is known about the biological mechanisms controlling their ratio. Here we present the structure of the magnetosome-associated protein MamP and find that it is built on a unique arrangement of a self-plugged PDZ domain fused to two magnetochrome domains, defining a new class of c-type cytochrome exclusively found in magnetotactic bacteria. Mutational analysis, enzyme kinetics, co-crystallization with iron(II) and an in vitro MamP-assisted magnetite production assay establish MamP as an iron oxidase that contributes to the formation of iron(III) ferrihydrite eventually required for magnetite crystal growth in vivo. These results demonstrate the molecular mechanisms of iron management taking place inside the magnetosome and highlight the role of magnetochrome in iron biomineralization.

[1] Nature, 502, 681–684 (2013)


12h15 Lunch

14hMarius Réglier (invited)
Aix Marseille Université, CNRS, ISM2 UMR 7313, Marseille.
«Inhibition of Tyrosinase, a coordination chemistry approach»

Tyrosinases are ubiquitous Cu-containing enzymes belonging to the type-3 or “coupled binuclear” family (Fig. 1). Ty’s catalyze the two-step oxidation of phenolic compounds into the corresponding catechols (monophenolase activity) and ortho-quinones (catecholase activity). In mammals, their biological function is to convert L-tyrosine into dopaquinone, which is the key product for melanin pigment biosynthesis. Melanin-related disorders are known to cause serious skin lesions, Parkinson’s disease and melanoma. In addition, Ty’s are responsible for the browning of plant foods, which creates an important economic problem in the field of nutrition. Ty inhibition is a well-established approach for controlling in vivo melanin production and food browning, so the development of Ty inhibitors has a huge economical and industrial impact. To control the Ty activity, the best strategy is to target the Ty binuclear copper active site by transition state analogues, which have structural analogies to catechol but are not oxidizable. Recently, we reported on HOPNO as TS analogues featuring competitive inhibition constants below to 1 M (Fig. 2) [1]. In this communication, we will describe our strategy to develop efficient Ty inhibitors derived from HPNO and aurones. Our approach includes synthetic chemistry and enzymology as well as structure-function studies using structural and functional models (Fig. 3) of the Ty active site [2-5].
***

Figure 1. Structure of the active site of the met2 Ty.

Figure 2. HOPNO and aurones (1-2).

Figure 3. Ty structural model in interaction with HOPNO.

[1] E. Peyroux, W. Ghattas, R. Hardré, M. Giorgi, B. Faure, A. J. Simaan, C. Belle, M. Réglier Inorg. Chem. 2009, 48, 10874. [2] M. Orio, C. Bochot, C. Dubois, G. Gellon, R. Hardré, H. Jamet, D. Luneau, C. Philouze, M. Réglier, G. Serratrice, C. Belle Chem. Eur. J. 2011, 17, 13482. [3] C. Dubois, R. Haudecoeur, M. Orio, C. Belle, C. Bochot, A. Boumendjel, R. Hardré, H. Jamet, M. Réglier ChemBioChem 2012, 13, 559. [4] C. Bochot, E. Favre, C. Dubois, B. Baptiste, L. Bubacco, P.-A. Carrupt, G. Gellon, R. Hardré, D. Luneau, Y. Moreau, A. Nurisso, M. Réglier, G. Serratrice, C. Belle, H. Jamet Chem. Eur. J. 2013, 19, 3655.5 C. Bochot, A. Gouron, L. Bubacco, A. Milet, C. Philouze, M. Réglier, G. Serratrice, H. Jamet and C. Belle. Chem. Commun. 2014, 50, 308.


14h30Pierre Rousselot Pailley, Marianthi Kafentzi, Yasmina Mekmouche, Eloine Npetgat, Viviane Robert, Ludovic Schneider, Jalila A. Simaan, Thierry Tron.
ISM2 UMR 7313, CNRS, Aix-Marseille Université 13397 Marseille cedex 20, France.
E-mail: pierre.rousselot-pailley@univ-amu.fr
"Toward new artificial enzymes based on Laccase."

Laccases are very well known biocatalysts with great robustness, high oxidation power and substrate versatility (among other properties) [1]. Laccases contain a unique set of copper ions made of at least one each of the three types of biorelevant copper sites: type 1 (T1), type 2 (T2) and a binuclear type 3 (T3), and couple dioxygen reduction to the oxidation of substrates, either organic or metal ion [2]. We aim at shaping new catalysts using the enzyme as a platform functionalized with “plug-ins” [3, 4].
One of our targets is to develop robust systems where light absorption triggers electron transfer events that subsequently lead to the activation of a catalytic centre.
Another target is the design of artificial enzymes for enantioselective synthesis adding organic modules to the enzyme.
This two aspects will be presented in this communication.
key words: Copper enzyme- photoinduced electron transfer - dioxygen

[1] Tron T., Laccases, in Encyclopedia of Metalloproteins, Kretsinger, RH, Uversky, VN, Permyakov, EA. (Eds.) Springer, 2013, 1300 p. [2] Solomon EI, Sundaram UM, Machonkin TE. Multicopper oxidases and oxygenases. Chem. Rev. 1996, 96 : 2563-2605. [3] Balland V, Hureau C, Cusano AM, Liu Y, Tron T, Limoges B. Oriented immobilization of a fully active monolayer of histidine-tagged recombinant laccase on modified gold electrodes. Chem. Eu. J. 2008, 14 :7186-92.[4] Robert V, MekmoucheY, Rousselot Pailley P, Tron T. Engineering laccases: in search for novel catalysts. Curr. Genomics 2011, 12: 123-129


15h Conchín Melía a, Silvia Ferrer a, Jan Řezáč b, Olivier Parisel c, Olivia Reinaud d, Vicent Moliner a, Aurélien de la Lande e:
a: Universitat Jaume I, 12071 Castelló (Spain), b: Academy of Sciences of the Czech Republic Flemingovo nam. 2, 166 10 Prague 6 (Czech Republic), c : Laboratoire de Chimie Théorique UPMC, CNRS, UMR 7616, d : Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes PRES Sorbonne Paris Cité, CNRS UMR 8601 (France), e : Laboratoire de Chimie Physique – CNRS UMR 8000. Université Paris-Sud. (France) aurelien.de-la-lande@u-psud.fr
Computational Investigation of the hydroxylation mechanism of noncoupled copper oxygenases

In Nature peptidylglycine a-hydroxylating monooxygenase (PHM), Dopamine b-monooxygenase (DbM) and Tyramine b-monooxygenase (TbM) are known to achieve the remarkable dioxygen-dependent hydroxylation of aliphatic C-H bonds using two uncoupled copper sites.[1] In spite of many investigations, either biochemical, chemical or computational, the details of the C-H bond oxygenation mechanism remain elusive; conflicting proposals have been advanced in the recent literature for the enzymatic catalytic cycle. [2] I will present an investigation of the hydroxylation mechanism of PHM using ab initio Molecular Dynamics simulations based on hybrid Density Functional Theory-classical potentials (ie. QM/MM). This computational scheme permits the inclusion of the intrinsic dynamics of the active site into the modeling strategy. The major result of this study has been an extremely fast (picoseconds timescale) rebound after the initial H-abstraction step promoted by the cupric-superoxide adduct. The H-abstraction/Rebound sequence leads to the formation of an alkylhydroperoxide intermediate. A long range electron transfer from the remote copper site subsequently triggers its reduction to the hydroxylated substrate.[3] The characteristic time scale of the rebound step (ps) suggests that it is very probably the fastest reactive pathway over the previously advanced proposals. Moreover, our proposal finds favorable echoes with recent experimental results obtained on biomimtic complexes.5 Overall our study sheds new lights on how PHM achieves hydroxylation of C-H bonds with two uncoupled copper sites.

[1] a) Osborne R.L.; Klinman, J. P. "Copper Oxygen Chemistry", pp 1-22; 2011, Ed. Karlin, K. D.; Itoh, S. Pub. J. Wiley & Sons. b) Solomon, E. I. et al. Chem. Rev. ASAP. DOI: 10.1021/cr400327t [2] see for example scheme 2 of N. R. McIntyre, E. W. Lowe Jr., D. J. Merkler, J. Am. Chem. Soc. 2009, 131, 10308 –10319. [3] Melía C., Ferrer S., Řezáč J., Parisel O., Reinaud O., Moliner V., de la Lande A. Chem. Eur. J. 2013, 19, 17328 – 17337. [4] de la Lande A., Parisel O., Moliner V. J. Am. Chem. Soc. 2007, 129,11700-11707. [5] a) Izzet, G., Zeitouny, J., Akdas-Killig, H., Frapart, Y., Ménage, S., Douziech, B., Jabin, Y., Le Mest, Y, Reinaud,O. J. Am. Chem. Soc. 2008, 130, 9514 –9523. b) Thiabaud, G. Guillemot, G., Schmitz-Afonso, I., Colasson, B. Reinaud, Angew. Chem. Int. Ed. 2009, 48, 7383 –7386. c) Tano, T., Sugimoto, H., Fujieda, N., Itoh, S. Eur. J. Inorg. Chem. 2012, 4099–4103.



15h30 Break

16h Ling PENG
Aix-Marseille Université, Centre Interdisciplinaire de Nanoscience de Marseille, CINaM
CNRS UMR 7325, Campus de Luminy, 13288 Marseille, France
"Bioinspired mixed ligand catalysts for powerful and green synthesis"

Nature has generated the most powerful and efficient catalysis through evolution, inspiring scientists to create novel and effective catalysts for chemical synthesis. Transition metal-catalyzed reactions developed by chemists have fundamentally revolutionized organic synthesis, empowering the otherwise difficult to achieve products with rapid and convenient accesses alongside excellent yields. Within these reactions, ligands often play a critical role in specifically and effectively advocating the corresponding catalysis. “Mixed ligand” concept has emerged, by combining and capitalizing on the superiority of each individual ligand already available, to promise an expedient way to reach a larger extend of catalytic diversity and efficacy [1-2]. the availability of a wealth of ligands, it is reasonable to have great expectations for the original application of mixed ligand catalytic systems and their important value in organic synthesis [3-5].

[1] M. T. Reetz, Angew. Chem., Int. Ed. 2008, 47, 2556-2588. [2] Y. Fan, M. Cong, L. Peng, Chem.-Eur. J. 2014, 20, 2698. [3] B. P. Fors, S. L. Buchwald, J. Am. Chem. Soc. 2010, 132, 15914-15917 [4] Y. Fan, Y. Xia, J. Tang, F. Ziarelli, F. Qu, P. Rocchi, J. L. Iovanna, L. Peng, Chem.-Eur. J. 2012, 18, 2221-2225 5. M. Cong, Y. Fan, J.-M. Raimundo, Y. Xia, Y. Liu, G. Quéléver, F. Qu, L. Peng, Chem.-Eur. J. 2013, 19, 17267-17272.


17hPierre Ceccaldi a, Léa Sylvi b, Axel Magalon b, Christophe Léger a and Vincent Fourmond a
a Unité de Bioénergétique et Oingénierie des Protéines (BIP), UMR7281, Institut de Microbiologie de la Méditerranée (IMM), FR7419, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
b Laboratoire de Chimie Bactérienne (LCB), UMR 7283, Institut de Microbiologie de la Méditerranée (IMM), FR7419, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
"Reductive Activation of E. coli Respiratory Nitrate Reductase"
Email: pceccaldi@imm.cnrs.fr

Prokaryotic nitrate reductases (NR) are molybdoenzymes that contain a Mo-bisPGD cofactor and catalyze the reduction of nitrate to nitrite. Several research groups have studied these enzymes, notably the spectroscopic signatures of the molybdenum cofactor (MoCo) [1-3] and the electron transfer chain [4]. For a decade, direct electrochemistry methods have been applied to probe the physical and chemical properties of the active site during catalysis [5-7]. Field and coworkers revealed that two prokaryotic NRs from Paracoccus pantotrophus (Pp) and Synechococcus elongatus (Se) activate upon reduction [7]. Elliott and coworkers have studied the respiratory NR from E. coli (EcNR) and proposed a catalytic cycle [6], but its activation had not been reported. We used chronoamperommetric methods to reveal that EcNR activates upon reduction, as observed with Pp and Se NRs [7-8]. We showed that 30 % of the sample activates upon reduction, and that kinetics of activation depends on redox conditions in a complex manner. We propose a kinetic model for the reductive activation of EcNR, which may be related to that of other Mo-bisPGD enzymes, such as DMSO reductase [9] or periplasmic NR [10].

[1] Vincent SP. And Bray RC, 1976, Biochem J., 1976, 155, 201. [2] Graham N. George, Bray RC, Morpeth FF, Boxer DH, 1985, Biochem J., 227, 925. [3] Axel Magalon, Marcel Asso, Bruno Guigliarelli, et al., 1998, Biochemistry, 37, 7363. [4] Bruno Guigliarelli, Axel Magalon, Marcel Asso et al., Biochemistry, 35, 4828. [5] Lee J. Anderson, David J. Richardson, Julea N.Butt, 2001, Biochemistry, 40, 11294. [6] Sean J. Elliott, Kevin R. Hoke, Kerensa Heffron, et al., 2004, Biochemistry, 43, 799. [7] Sarah J. Field, Nicholas P. Thornton, Lee J. Anderson, 2005, Dalton Transactions, 3580. [8] Vincent Fourmond, Pascale Infossi, Marie-Thérèse Giudici-Orticoni et al., 2010, J Am Chem Soc., 132, 4848. [9] James C. Hilton, Carrie A. Temple, and K. V. Rajagopalan, 1999, JBC, 274, 8428.10 Julien G. Jacques, Vincent Fourmond, Pascal Arnoux et al., 2014, Biochim Biophys Acta, 1837, 277.


17h30Stéphane Ménage (invited)
Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, UMR 5249-CNRS, iRTSV CEA Grenoble, 17, avenue des Martyrs, 38054 Genoble Cedex, France.
"A Green Approach for Oxidation Catalysis: Design of Artificial (mono)dioxygenases"

The need for a sustainable chemistry urges on the scientific community to design new cleaner chemical processes. In this context, White biotechnology is then an attractive approach by transferring concepts from a living world to a new synthetic chemistry world. But, in this field, there is still a need for basic research to design efficient enzymes. As a matter of fact, their use in industrial applications still suffers from the lack of knowledge on their modes of reactivity and their lack of stability. To design new biocatalysts for a defined reaction, different approaches have been developed: i) site-directed mutagenesis or directed evolution of natural enzymes to switch their activity and/or increase their stability, ii) the design of artificial metalloenzymes, based on the combination of metal-based catalysis (by an inorganic complex) and protein-driven reaction selectivity, conferring unnatural activities to biomolecules.[1] Compared to natural enzymes, the advantage of these hybrids resides on an additional degree of optimization based on structural modifications of the inorganic complex embedded within the protein. In addition, these systems also afford news insights for the enzymatic reaction control, since protein environment and catalytic site can be studied separately.
The presentation deals with the design of original metalloenzymes for dioxygen activation using our own technology based based on the insertion of inorganic catalysts into the periplasmic nickel-binding protein NikA via supramolecular interactions to convert it from a transport protein to a metalloenzyme.[2] First, we will discuss a new concept for the understanding of catalysis mechanism using the combination of protein X-ray crystallography and inorganic catalysis.[3] The targeted reaction concerns the aromatic hydroxylation by dioxygen catalyzed by an iron complex. Second, a new type of oxidase will be presented, using iron complexes known as catalysts for C-H, C=C, C-OH and oxygen transfer to sulfides.[4] Finally, we have developed a new method to create new enzyme based on the search for sulfides enzyme substrates using an original screening approach. This work highlighted the importance of the synergetic effect of the different partners, i.e. the protein, the inorganic complex and the substrate.

[1] (a) T. Ueno, S. Abe, N. Yokoi, Y. Watanabe, Coord. Chem. Rev. 2007, 251, 2717-2731; (b) J. Steinreiber, T. R. Ward, Coord. Chem. Rev. 2008, 252, 751-766; (c) T. R. Ward, in Top. Organomet. Chem., Vol. 25, Springer, Verlag Berlin Heidelberg, 2009; (d) Y. Lu, N. Yeung, N. Sieracki, N. M. Marshall, Nature 2009, 460, 855-862; (e) A. J. Boersma, R. P. Megens, B. L. Feringa, G. Roelfes, Chem. Soc. Rev. 2010, 39, 2083-2092; [2] Cherrier, M.V. et al. J. Am. Chem. Soc. 2005, 127, 10075-10082. [3] Cavazza et al. Nature Chemistry 2010, 2, 1069. [4] M. Cherrier, E. Girgenti, P. Amara, M. Iannello, C. Marchi-Delapierre, J. Fontecilla-Camps, S. Ménage, C. Cavazza, J. Biol. Inorg. Chem. 2012, 17, 817-829.