AgreenSkills session, year: 1st session, 2015
Receiving laboratory: IKBM Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Norway
Country of origin : Norway
Structure-function studies of lytic polysaccharide monooxygenases, novel tools for enzymatic biomass conversion
The deconstruction of recalcitrant polysaccharides such as chitin or cellulose, but also that of hemicellulose or starch, was recently (2010) demonstrated to require the oxidative action of enzymes named lytic polysaccharide monooxygenases (LPMOs), reclassified as auxiliary activities within the CAZymes database. LPMOs are copper-dependent enzymes that catalyze the oxidation of glycosidic bonds via a still rather unclear mechanism, involving molecular oxygen as well as electron donors. This post-doctoral project aims at, on one hand, providing fundamental insight into the LPMOs mechanism (notably development of new electron providing systems) and, on the other hand, elucidating the molecular features involved in substrate specificity divergence that occurred along natural evolution.
In the course of my studies I got specialized in biochemical engineering with a focus on biocatalysis (INSA of Toulouse, France). Enzymes being the workhorses of most of the chemical reactions occurring inside and around us, I found very exciting the perspective of being involved in the understanding of how these work and how their activity can be engineered. Allying both fundamental science and concrete applications I decided to focus my scientific activities on the deciphering and engineering of enzymes mechanisms in relationship with environmental issues. Indeed, such biocatalysts will no doubt benefit to a larger public in medium and long terms with respect to the development of greener and more sustainable processes in the frame of the emerging bio-economy.
During my PhD thesis (2011-2014, INSA), guided by Prof. Em. P. Monsan and Dr M. O’Donohue, I devoted my time to the understanding of how enzymatic tools for glycosynthesis could rationally be engineered using the vast biodiversity of hydrolytic Glycoside Hydrolases as starting material. From the analysis of the literature published during the past 20 years a global rationale was depicted in a review entitled “Glycosynthesis in a Waterworld”. Experimentally a specific focus was made on furanose-acting enzymes, leading to the creation of the first non-Leloir transarabinofuranosylases artificially evolved from an α-l-arabinofuranosidase, which naturally hydrolyses plant cell wall arabinoxylans. Those new glycosynthetic tools allowed the in vitro design of tailor-made pentose/furanoses-based oligosaccharides, providing compounds potentially harboring a wide variety of properties from prebiotics to bio-inspired materials.
I then turned my attention towards the mysteries of the recently discovered lytic polysaccharides monooxygenases (LPMO), under the supervision of Profs G. Vaaje-Kolstad and V. Eijsink (NMBU, Aas, Norway). Those enzymes are essential for the deconstruction of complex polysaccharides (cellulose, chitin, starch, etc…) and I aim on one hand to contribute to the elucidation of their catalytic mechanism and, on the other hand, to shed light on the evolution of their substrate specificity.
1- Bissaro, Bastien; Durand, Julien ; Biarnés, Xevi ; Planas, Antoni ; Monsan, Pierre ; J. O’Donohue, Michael and Fauré, Régis. Molecular Design of non-Leloir furanose-transferring enzymes from an α-l-arabinofuranosidase : A rationale for the engineering of evolved transglycosylases. ACS Catalysis, 5, 8, 4598-4611.
2- Bissaro, Bastien; Monsan, Pierre; Fauré, Régis; O’Donohue, Michael J.; Glycosynthesis in a waterworld: new insight into the molecular basis of transglycosylation in retaining glycoside hydrolases., Biochem J., 467, 1, 17-35, 2015. Review
3- Arab-Jaziri, Faten; Bissaro, Bastien; Tellier, Charles; Dion, Michel; Fauré, Régis; O’Donohue, Michael J. Enhancing the chemoenzymatic synthesis of arabinosylated xylo-oligosaccharides by GH51 α-l-arabinofuranosidase, Carbohydrate research, 401, 64-72, 2015.
4- Bissaro, Bastien; Saurel, Olivier; Arab-Jaziri, Faten; Saulnier, Luc; Milon, Alain; Tenkanen, Maija; Monsan, Pierre; O’Donohue, Michael J; Fauré, Régis. Mutation of a pH-modulating residue in a GH51 α-l-arabinofuranosidase leads to a severe reduction of the secondary hydrolysis of transfuranosylation products, Biochimica et Biophysica Acta (BBA)-General Subjects, 1840, 1, 626-636, 2014.
5- Bissaro, Bastien*; Arab-Jaziri, Faten*; Dion, Michel; Saurel, Olivier; Harrison, David; Ferreira, Fernando; Milon, Alain; Tellier, Charles; Fauré, Régis; O’Donohue, Michael J. Engineering transglycosidase activity into a GH51 α-l-arabinofuranosidase, New biotechnology, 30, 5, 536-544, 2013.
6-Bissaro, Bastien*; Arab‐Jaziri, Faten*; Barbe, Sophie; Saurel, Olivier; Débat, Hélène; Dumon, Claire; Gervais, Virginie; Milon, Alain; André, Isabelle; Fauré, Régis. Functional roles of H98 and W99 and β2α2 loop dynamics in the α‐l‐arabinofuranosidase from Thermobacillus xylanilyticus, FEBS Journal, 279, 19, 3598-3611, 2012.
* : co-first authors
Awarded outstanding poster presentation at Gordon Research Conferences (Andover, USA, August, 2015)
AgreenSkill-Marie Curie Fellowship (FP7 COFUND) – 2015/2016
Obtained Doctoral research fellow of Excellence from INRA (Young Scientist 5-year Contract)
Awarded outstanding poster presentation at 10th Carbohydrate Bioengineering Meeting (Prague, April, 2013)
Awarded best poster presentation (Sevab d’Or) during Doctoral School Conferences (Toulouse, November, 2011)