@article{pmid38938184,

title = {Multivalent inhibition of the  fumigatus KDNase},

author = {Mathieu Scalabrini and Denis Loquet and Camille Rochard and Mélyne Baudin Marie and Coralie Assailly and Yoan Brissonnet and Franck Daligault and Amélie Saumonneau and Annie Lambert and Cyrille Grandjean and David Deniaud and Paul Lottin and Sagrario Pascual and Laurent Fontaine and Viviane Balloy and Sébastien G Gouin},

doi = {10.1039/d4ob00601a},

issn = {1477-0539},

year  = {2024},

date = {2024-07-01},

urldate = {2024-07-01},

journal = {Org Biomol Chem},

volume = {22},

number = {28},

pages = {5783--5789},

abstract = { is a saprophytic fungus and opportunistic pathogen often causing fatal infections in immunocompromised patients. Recently KDNAse, an exoglycosidase hydrolyzing 3-deoxy-D-galacto-D--nonulosonic acid (KDN), a rare sugar from the sialic acid family, was identified and characterized. The principal function of KDNAse is still unclear, but a study suggests a critical role in fungal cell wall morphology and virulence. Potent KDNAse inhibitors are required to better probe the enzyme's biological role and as potential antivirulence factors. In this work, we developed a set of KDNAse inhibitors based on enzymatically stable thio-KDN motifs. C2, C9-linked heterodi-KDN were designed to fit into unusually close KDN sugar binding pockets in the protein. A polymeric compound with an average of 54 KDN motifs was also designed by click chemistry. Inhibitory assays performed on recombinant KDNAse showed a moderate and strong enzymatic inhibition for the two classes of compounds, respectively. The poly-KDN showed more than a nine hundred fold improved inhibitory activity (IC = 1.52 ± 0.37 μM, 17-fold in a KDN molar basis) compared to a monovalent KDN reference, and is to our knowledge, the best synthetic inhibitor described for a KDNase. Multivalency appears to be a relevant strategy for the design of potent KDNase inhibitors. Importantly, poly-KDN was shown to strongly decrease filamentation when co-cultured with  at micromolar concentrations, opening interesting perspectives in the development of antivirulence factors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{SAUMONNEAU2023101335,

title = {Disruption of Botryococcus braunii colonies by glycoside hydrolases},

author = {Amélie Saumonneau and Nathan Lagneau and Lydia Awuor Ogonda and Catherine Dupré and Stéphanie Dutertre and Dominique Grizeau and Charles Tellier and Cyrille Grandjean and Franck Daligault},

url = {https://www.sciencedirect.com/science/article/pii/S2589014X23000063

hal-03973352v1 },

doi = {10.1016/j.biteb.2023.101335},

issn = {2589-014X},

year  = {2023},

date = {2023-01-13},

urldate = {2023-01-13},

journal = {Bioresource Technology Reports},

volume = {21},

pages = {101335},

abstract = {Microalgae are a promising alternative resource to fossil-based products. Botryococcus braunii is a colonial green microalga having the ability to convert CO2 by photosynthesis into long chain hydrocarbons. These are excreted and trapped in an extracellular matrix (ECM). A panel of glycosidases ranging from arabinanase, galactananase to endoglucanase was tested for their ability to lyse the polysaccharides maintaining the B. braunii colony integrity in order to release the hydrocarbons present in the extracellular matrix without harming the cells. The BpGH9 endoglucanase from Bacillus pumilus was fused with CtCBM3a from Clostridium thermocellum and yellow fluorescent protein to probe the presence of microcrystalline cellulose in the cell wall of B. braunii and to increase the efficacy of the endoglucanase. All the tested enzymes were able to some extent to dissociate the cells from the extracellular matrix while keeping them alive, suggesting the feasibility of a semi-continuous in situ recovery of hydrocarbons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/chem.202004672,

title = {Polyvalent Transition-State Analogues of Sialyl Substrates Strongly Inhibit Bacterial Sialidases**},

author = {Coralie Assailly and Clarisse Bridot and Amélie Saumonneau and Paul Lottin and Benoit Roubinet and Eva-Maria Krammer and Francesca François and Federica Vena and Ludovic Landemarre and Dimitri Alvarez Dorta and David Deniaud and Cyrille Grandjean and Charles Tellier and Sagrario Pascual and Véronique Montembault and Laurent Fontaine and Franck Daligault and Julie Bouckaert and Sébastien G Gouin},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202004672},

doi = {https://doi.org/10.1002/chem.202004672},

year  = {2021},

date = {2021-01-01},

journal = {Chemistry – A European Journal},

volume = {27},

number = {9},

pages = {3142-3150},

abstract = {Abstract Bacterial sialidases (SA) are validated drug targets expressed by common human pathogens such as Streptococcus pneumoniae, Vibrio cholerae, or Clostridium perfringens. Noncovalent inhibitors of bacterial SA capable of reaching the submicromolar level are rarely reported. In this work, multi- and polyvalent compounds are developed, based on the transition-state analogue 2-deoxy-2,3-didehydro-N-acetylneuraminic (DANA). Poly-DANA inhibits the catalytic activity of SA from S. pneumoniae (NanA) and the symbiotic microorganism B. thetaiotaomicron (BtSA) at the picomolar and low nanomolar levels (expressed in moles of molecules and of DANA, respectively). Each DANA grafted to the polymer surpasses the inhibitory potential of the monovalent analogue by more than four orders of magnitude, which represents the highest multivalent effect reported so far for an enzyme inhibition. The synergistic interaction is shown to operate exclusively in the catalytic domain, and not in the flanked carbohydrate-binding module (CBM). These results offer interesting perspectives for the multivalent inhibition of other SA families lacking a CBM, such as viral, parasitic, or human SA.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ogondacharacterization,

title = {Characterization and engineering of two new GH9 and GH48 cellulases from a Bacillus pumilus isolated from Lake Bogoria},

author = {Lydia A Ogonda and Amélie Saumonneau and Michel Dion and Edward K Muge and Benson M Wamalwa and Francis J Mulaa and Charles Tellier},

doi = {10.1007/s10529-020-03056-z},

year  = {2021},

date = {2021-01-01},

journal = {Biotechnology Letters},

volume = {43},

pages = {691–700},

publisher = {Springer},

abstract = {Objectives. To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering 

Results. Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose. 

 Conclusions. A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Brissonnet2019b,

title = {Multivalent Thiosialosides and Their Synergistic Interaction with Pathogenic Sialidases},

author = {Yoan Brissonnet and Coralie Assailly and Amélie Saumonneau and Julie Bouckaert and Mike Maillasson and Clémence Petitot and Benoit Roubinet and Blanka Didak and Ludovic Landemarre and Clarisse Bridot and Ralf Blossey and David Deniaud and Xibo Yan and Julien Bernard and Charles Tellier and Cyrille Grandjean and Franck Daligault and Sébastien G Gouin},

doi = {10.1002/chem.201805790},

issn = {15213765},

year  = {2019},

date = {2019-01-01},

journal = {Chemistry - A European Journal},

volume = {25},

number = {9},

pages = {2358--2365},

abstract = {Sialidases (SAs) hydrolyze sialyl residues from glycoconjugates of the eukaryotic cell surface and are virulence factors expressed by pathogenic bacteria, viruses, and parasites. The catalytic domains of SAs are often flanked with carbohydrate-binding module(s) previously shown to bind sialosides and to enhance enzymatic catalytic efficiency. Herein, non-hydrolyzable multivalent thiosialosides were designed as probes and inhibitors of V. cholerae, T. cruzi, and S. pneumoniae (NanA) sialidases. NanA was truncated from the catalytic and lectinic domains (NanA-L and NanA-C) to probe their respective roles upon interacting with sialylated surfaces and the synthetically designed di- and polymeric thiosialosides. The NanA-L domain was shown to fully drive NanA binding, improving affinity for the thiosialylated surface and compounds by more than two orders of magnitude. Importantly, each thiosialoside grafted onto the polymer was also shown to reduce NanA and NanA-C catalytic activity with efficiency that was 3000-fold higher than that of the monovalent thiosialoside reference. These results extend the concept of multivalency for designing potent bacterial and parasitic sialidase inhibitors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Alvarez-Dorta2017,

title = {Magnetic Nanoparticles Coated with Thiomannosides or Iminosugars to Switch and Recycle Galactosidase Activity},

author = {Dimitri Alvarez-Dorta and Yoan Brissonnet and Amélie Saumonneau and David Deniaud and Julien Bernard and Xibo Yan and Charles Tellier and Franck Daligault and Sébastien G Gouin},

doi = {10.1002/slct.201702063},

issn = {23656549},

year  = {2017},

date = {2017-01-01},

journal = {ChemistrySelect},

volume = {2},

number = {29},

pages = {9552--9556},

abstract = {Glycosidase effectors have rarely been reported despite their great potential interest in pharmaceutical sciences and industry. Magnetic nanoparticles were coated with thiomannosides (SMan@Fe3O4) or the broad spectrum glycosidase inhibitor deoxynojirimycin (DNJ@Fe3O4). The coated ligands were shown to exert a fully reverse effect on a model galactosidase (AgaB), with SMan@Fe3O4 or DNJ@Fe3O4 ligands acting as an enzyme inhibitor (Ki=3.7 µM) or a strong activator (250% higher AgaB velocity at 50 µM), respectively. This is striking considering that monovalent soluble SMan and DNJ analogues do not interact with AgaB at millimolar concentrations. The AgaB-DNJ@Fe3O4 enzyme-effector complex could be magnetically recycled and still showed a higher activity compared to free AgaB after four catalytic cycles. The “boost and recycle” procedure may provide interesting perspectives in glycosidase biocatalysis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Saumonneau2015a,

title = {Design of an α-l-transfucosidase for the synthesis of fucosylated HMOs},

author = {Amélie Saumonneau and Elise Champion and Pauline Peltier-Pain and Dora Molnar-Gabor and Johann Hendrickx and Vinh Tran and Markus Hederos and Gyula Dekany and Charles Tellier},

doi = {10.1093/glycob/cwv099},

issn = {14602423},

year  = {2015},

date = {2015-01-01},

journal = {Glycobiology},

volume = {26},

number = {3},

pages = {261--269},

abstract = {Human milk oligosaccharides (HMOs) are recognized as benefiting breast-fed infants in multiple ways. As a result, there is growing interest in the synthesis of HMOs mimicking their natural diversity. Most HMOs are fucosylated oligosaccharides. α-l-Fucosidases catalyze the hydrolysis of α-l-fucose from the non-reducing end of a glucan. They fall into the glycoside hydrolase GH29 and GH95 families. The GH29 family fucosidases display a classic retaining mechanism and are good candidates for transfucosidase activity. We recently demonstrated that the α-l-fucosidase from Thermotoga maritima (TmαFuc) from the GH29 family can be evolved into an efficient transfucosidase by directed evolution (Osanjo et al. 2007). In this work, we developed semi-rational approaches to design an α-l-transfucosidase starting with the α-l-fucosidase from commensal bacteria Bifidobacterium longum subsp. infantis (BiAfcB, Blon-2336). Efficient fucosylation was obtained with enzyme mutants (L321P-BiAfcB and F34I/L321P-BiAfcB) enabling in vitro synthesis of lactodifucotetraose, lacto-N-fucopentaose II, lacto-N-fucopentaose III and lacto-N-difucohexaose I. The enzymes also generated more complex HMOs like fucosylated para-lacto-N-neohexaose (F-p-LNnH) and mono- or difucosylated lacto-N-neohexaose (F-LNnH-I, F-LNnH-II and DF-LNnH). It is worth noting that mutation at these two positions did not result in a strong decrease in the overall activity of the enzyme, which makes these variants interesting candidates for large-scale transfucosylation reactions. For the first time, this work provides an efficient enzymatic method to synthesize the majority of fucosylated HMOs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}