Baptiste Legrand

Baptiste legrand
Research Engineer, University of Montpellier (UM)

Baptiste is a Research Engineer at the Institute of Biomolecules Max Mousseron (IBMM), University of Montpellier. He received his PhD in biology and life sciences from the University of Rennes 1 in 2009. Then, he moved for a two years post-doctoral fellowship at the Laboratory of Macromolecular Chemistry and Physics (LCPM, Nancy) working on the characterization of foldamers structures combining various techniques (NMR, CD and FTIR spectroscopies, and Molecular Dynamics) and then he joined the IBMM in 2012. His research is mainly devoted on the rational design of peptidomimetics and organized molecular architectures to modulate biological processes focusing on the structural aspects. He is in charge of the conformational studies of various chemical tools developed at the IBMM but also collaborates with other groups.

Contact:
baptiste.legrand@umontpellier.fr
+33 411 75 96 06

5 major publications :

Legrand B, André C, Moulat L, Didierjean C, Hermet P, Bantignies JL, Martinez J, Amblard M, Calmès M. 12/14/14-Helix Formation in 2:1 α/β-Hybrid Peptides Containing Bicyclo[2.2.2]octane Ring Constraints. Chemistry. 2016. 16;22(34):11986-90.

Martin V, Legrand B, Vezenkov LL, Subra G, Calmès M, Bantignies J.L, Martinez J,  Amblard M. Turning Peptide Sequences into Ribbon Foldamers by a Straightforward Multicyclization Reaction. Angew. Chem. Int. Ed. 2015. 16;54(47):13966-70.

Legrand B, André C, Moulat L, Wenger E, Didierjean C, Aubert E, Averlant-Petit MC, Martinez J, Calmes M, Amblard M. Unprecedented chain-length-dependent conformational conversion between 11/9 and 18/16 helix in α/β-hybrid peptides. Angew Chem Int Ed. 2014. 53(48):13131-5.

Mathieu L, Legrand B, Deng C, Vezenkov L, Wenger E, Didierjean C, Amblard M, Averlant-Petit MC, Masurier N, Lisowski V, Martinez J, Maillard LT. Helical oligomers of thiazole-based γ-amino acids: synthesis and structural studies. Angew Chem Int Ed. 2013. 3;52(23):6006-10.

Legrand B, André C, Wenger E, Didierjean C, Averlant-Petit MC, Martinez J, Calmes M, Amblard M. Robust helix formation in a new family of oligoureas based on a constrained bicyclic building block. Angew Chem Int Ed. 2012. 51(45):11267-70.

The HslV Protease from Leishmania major and Its Activation by C-terminal HslU Peptides

Int J Mol Sci. 2019 Feb 26;20(5). pii: E1021. doi: 10.3390/ijms20051021

Kebe NM, Samanta K, Singh P, Lai-Kee-Him J, Apicella V, Payrot N, Lauraire N, Legrand B, Lisowski V, Mbang-Benet DE, Pages M, Bastien P, Kajava AV, Bron P, Hernandez JF, Coux O

Abstract

HslVU is an ATP-dependent proteolytic complex present in certain bacteria and in the mitochondrion of some primordial eukaryotes, including deadly parasites such as Leishmania. It is formed by the dodecameric protease HslV and the hexameric ATPase HslU, which binds via the C-terminal end of its subunits to HslV and activates it by a yet unclear allosteric mechanism. We undertook the characterization of HslV from Leishmania major (LmHslV), a trypanosomatid that expresses two isoforms for HslU, LmHslU1 and LmHslU2. Using a novel and sensitive peptide substrate, we found that LmHslV can be activated by peptides derived from the C-termini of both LmHslU1 and LmHslU2. Truncations, Ala- and D-scans of the C-terminal dodecapeptide of LmHslU2 (LmC12-U2) showed that five out of the six C-terminal residues of LmHslU2 are essential for binding to and activating HslV. Peptide cyclisation with a lactam bridge allowed shortening of the peptide without loss of potency. Finally, we found that dodecapeptides derived from HslU of other parasites and bacteria are able to activate LmHslV with similar or even higher efficiency. Importantly, using electron microscopy approaches, we observed that the activation of LmHslV was accompanied by a large conformational remodeling, which represents a yet unidentified layer of control of HslV activation.

Stapled peptide targeting the CDK4/Cyclin D interface combined with Abemaciclib inhibits KRAS mutant lung cancer growth

Theranostics 2020; 10(5):2008-2028. doi:10.7150/thno.40971

Bouclier C*, Simon M*, Laconde G, Pellerano M, Diot S, Lantuejoul S, Busser B, Vanwonterghem L, Vollaire J, Josserand V, Legrand B, Coll JL, Amblard M, Hurbin A#, Morris MC#

* & # These authors contributed equally

Abstract

CDK4/cyclin D kinase constitutes an attractive pharmacological target for development of anticancer therapeutics, in particular in KRAS-mutant lung cancer patients, who have a poor prognosis and no targeted therapy available yet. Although several ATP-competitive inhibitors of CDK4 have been developed for anticancer therapeutics, they suffer from limited specificity and efficacy.

Methods: As an alternative to ATP-competitive inhibitors we have designed a stapled peptide to target the main interface between CDK4 and cyclin D, and have characterized its physico-chemical properties and affinity to bind cyclin D1.

Results: We have validated a positive correlation between CDK4/cyclin D level and KRAS mutation in lung cancer patients. The stapled peptide enters cells rapidly and efficiently, and inhibits CDK4 kinase activity and proliferation in lung cancer cells. Its intrapulmonary administration in mice enables its retention in orthotopic lung tumours and complete inhibition of their growth when co-administered with Abemaciclib.

Conclusion: The stapled peptide targeting the main interface between CDK4 and cyclin D provides promising therapeutic perspectives for patients with lung cancer.

Keywords: CDK4, Stapled Peptide, Inhibitor, Lung cancer (NSCLC), KRAS mutation

Prospect of Thiazole-based gamma-Peptides Foldamers in Enamine Catalysis: Exploration of the Nitro-Michael Addition

Chemistry. 2019 May 28;25(30):7396-7401. doi: 10.1002/chem.201901221. Epub 2019 May 7.

Aguesseau-Kondrotas J, Simon M, Legrand B, Bantigniès JL, Kang YK, Dumitrescu D, Van der Lee A, Campagne JM, de Figueiredo RM, Maillard LT.

Abstract

As three-dimensional folding is prerequisite to biopolymer activity, complex functions may also be achieved through foldamer science. Because of the diversity of sizes, shapes and folding available with synthetic monomers, foldamer frameworks enable a numerous opportunities for designing new generations of catalysts. We herein demonstrate that heterocyclic γ-peptide scaffolds represent a versatile platform for enamine catalysis. One central feature was to determine how the catalytic activity and the transfer of chiral information might be under the control of the conformational behaviours of the oligomer.

How are 1,2,3-triazoles accommodated in helical secondary structures?

Org Biomol Chem. 2018 May 15. doi: 10.1039/c8ob00686e

Ben Haj Salah K, Das S , Ruiz N , Andreu V , Martinez J , Wenger E , Amblard M , Didierjean C , Legrand B , Inguimbert N

Abstract

1,4-Disubstituted-1,2,3-triazole (Tz) is widely used in peptides as a trans-amide bond mimic, despite having hazardous effects on the native peptide activity. The impact of amide bond substitution by Tz on peptide secondary structures is scarcely documented. We performed a Tz scan, by systematically replacing peptide bonds following the Aib residues with Tz on two model peptaibols: alamethicin F50/5 and bergofungin D, which adopt stable α- and 310 helices, respectively. We observed that the Tz insertion, whatever its position in the peptide sequences, abolished their antimicrobial activity. The structural consequences of this insertion were further investigated using CD, NMR and X-ray diffraction. Importantly, five crystal structures that were incorporated with Tz were solved, showing various degrees of alteration of the helical structures, from minor structural perturbation of the helix to partial disorder. Together, these results showed that Tz insertions impair helical secondary structures.

12/10-Helix in Mixed β-Peptides Alternating Bicyclic and Acyclic β-Amino Acids: Probing the Relationship between Bicyclic Side Chain and Helix Stability

Chemistry. 2018 Dec 12. doi: 10.1002/chem.201804404. Epub 2018 Nov 15

Simon M, Milbeo P, Liu H, André C, Wenger E, Martinez J, Amblard M, Aubert E, Legrand B, Calmès M.

Abstract

12/10-Helices constitute suitable templates that can be used to design original structures. Nevertheless, they often suffer from a weak stability in polar solvents because they exhibit a mixed hydrogen-bond network resulting in a small macrodipole. In this work, stable and functionalizable 12/10-helices were developed by alternating a highly constrained β2, 3, 3 -trisubstituted bicyclic amino acid (S)-1-aminobicyclo[2.2.2]octane-2-carboxylic acid ((S)-ABOC) and an acyclic substituted β-homologated proteinogenic amino acid (l-β3 -hAA). Based on NMR spectroscopic analysis, it was shown that such mixed β-peptides display well-defined right-handed 12/10-helices in polar, apolar, and chaotropic solvents; that are, CD3 OH, CDCl3 , and [D6 ]DMSO, respectively. The stability of the hydrogen bonds forming the C10 and C12 pseudocycles as well as the benefit provided by the use of the constrained bicyclic ABOC versus typical acyclic β-amino acids sequences when designing 12/10-helix were investigated using NH/ND NMR exchange experiments and DFT calculations in various solvents. These studies showed that the β3 -hAA/(S)-ABOC helix displayed a more stable hydrogen-bond network through specific stabilization of the C10 pseudocycles involving the bridgehead NH of the ABOC bicyclic scaffold.

Synthesis of [1,2,4]Triazolo[4,3- a]piperazin-6-ones: An Approach to the Triazole-Fused Ketopiperazine Scaffold

Org Lett. 2018 Jun 1;20(11):3250-3254. doi: 10.1021/acs.orglett.8b01112. Epub 2018 May 15.

Ben Haj Salah K, Legrand B, Bibian M, Wenger E, Fehrentz JA, Denoyelle S.

Abstract

A stereoconservative synthesis to access the triazole-fused ketopiperazine (TKP) scaffold is presented. This underexplored platform offers a wide range of structural modulations with several points of diversity and chiral centers. A series of [1,2,4]triazolo[4,3- a]piperazin-6-ones was synthesized from optically pure dipeptides. The methodology was then successfully applied to access the pyrrolo[1,2- a]triazolo[3,4- c]piperazin-6-one tricycle. Importantly, the crystal structures of representative TKPs confirmed that the configuration of the chiral centers was controlled during the synthetic route and facilitated description of the orientation of the substituents depending on their nature and position on the TKP scaffold.

Selectivity Modulation and Structure of α/aza-β3 Cyclic Antimicrobial Peptides

Chemistry 2018 Apr 20;24(23):6191-6201. doi: 10.1002/chem.201800152. Epub 2018 Mar 26.

 Simon MLaurencin M, Fleury Y, Baudy-Floc’h M, Bondon A, Legrand B.

Abstract

Potent and selective antimicrobial cyclic pseudopeptides (ACPPs) mixing α- and aza-β3 -amino acids were developed. Cyclopseudopeptide sequences were designed to investigate the impact of some intrinsic molecular parameters on their biological activities. Fine changes in the nature of the side chains strongly modulated the selectivity of the ACPPs with regard to hemolysis versus antimicrobial activity. The conformational preference of such compounds in various media was extensively studied, and the typical structure of cyclic α/aza-β3 -pseudopeptides is described for the first time. Interestingly, such scaffolds are stabilized by successive inverse γ- and N-N turns (hydrazino turns), a unique feature due to the aza-β3 residues. The α-amino acid side chains form a cluster on one face of the ring, while the aza-β3 -amino acid side chains are projected around the ring in the equatorial orientation. Such structural data are particularly valuable to fine-tune the bioactivity of these ACPPs by a structure-based approach.

C9/12 Ribbon-Like Structures in Hybrid Peptides Alternating α- and Thiazole-Based γ-Amino Acids

Chemistry. 2017 Dec 11;23(69):17584-17591. doi: 10.1002/chem.201704001. Epub 2017 Nov 15.

Bonnel C, Legrand B, Simon M, Martinez J, Bantignies JL, Kang YK, Wenger E, Hoh F, Masurier N, Maillard LT.

Abstract

According to their restricted conformational freedom, heterocyclic γ-amino acids are usually considered to be related to Z-vinylogous γ-amino acids. In this context, oligomers alternating α-amino acids and thiazole-based γ-amino acids (ATCs) were expected to fold into a canonical 12-helical shape as described for α/γ-hybrid peptides composed of cis-α/β-unsaturated γ-amino acids. However, through a combination of X-ray crystallography, NMR spectroscopy, FTIR experiments, and DFT calculations, it was determined that the folding behavior of ATC-containing hybrid peptides is much more complex. The homochiral α/(S)-ATC sequences were unable to adopt a stable conformation, whereas the heterochiral α/(R)-ATC peptides displayed novel ribbon structures stabilized by unusual C9/12 -bifurcated hydrogen bonds. These ribbon structures could be considered as a succession of pre-organized γ/α dipeptides and may provide the basis for designing original α-helix mimics.

Ribbon-like Foldamers for Cellular Uptake and Drug Delivery

Chembiochem 2017 Nov 2;18(21):2110-2114. doi: 10.1002/cbic.201700455. Epub 2017 Sep 22.

Vezenkov LL, Martin V, Bettache N, Simon M, Messerschmitt A, Legrand B, Bantignies JL, Subra G, Maynadier M, Bellet V, Garcia M, Martinez J, Amblard M.

Abstract

Different intracellular delivery systems of bioactive compounds have been developed, including cell-penetrating peptides. Although usually nontoxic and biocompatible, these vectors share some of the general drawbacks of peptides, notably low bioavailability and susceptibility to protease degradation, that limit their use. Herein, the conversion of short peptide sequences into poly-α-amino-γ-lactam foldamers that adopt a ribbon-like structure is investigated. This template is used to distribute critical cationic and/or hydrophobic groups on both sides of the backbone, leading to potent short, cell-permeable foldamers with a low positive-charge content. The lead compound showed dramatically improved protease resistance and was able to efficiently deliver a biologically relevant cargo inside cells. This study provided a simple strategy to convert short peptide sequences into efficient protease-resistant cell-penetrating foldamers.

A General Approach to the Aza-Diketomorpholine Scaffold

Organic Letters, 2017, Volume: 19, Issue: 3, Pages: 492-495, DOI: 10.1021/acs.orglett.6b03656

M. Berthet, B. Legrand, J. Martinez, I. Parrot

Abstract

A stereoconservative three-step synthesis to access to 1,2,4-oxadiazine-3,6-dione is presented. This underexplored platform could be considered as a constrained oxy-azapeptide or an aza-diketomorpholine, the methodol. being then successfully applied to produce enantiopure aza-analogs of diketomorpholine natural products. Importantly, the 1st crystal structures were obtained and compared to diketomorpholine and diketopiperazine structures. Finally, a straightforward procedure concerning the coupling of this heterocyclic scaffold with various amino acids to afford original pseudodipeptide analogs was described.