Joelle Pelletier

Accredited Professor

Photo Pelletier 2010 + Marvin

Contact Information

Département de chimie
Faculté de médecine
Université de Montréal
Pavillon Roger-Gaudry, bureau F-507
C.P. 6128, Succ. Centre-ville
Montréal (Québec)
H3C 3J7


T 514 343-2124
F 514 343-7586
Site web


Our goal is to develop a deeper understanding of enzyme structure-function relationships so as to more readily modify enzymes for defined purposes. Enzyme modification is a promising field, with a growing number of major industries rapidly increasing their activities in this sector, notably because policy changes now encourage the use of environmentally-friendly catalysts such as enzymes. The power of enzyme engineering has increased dramatically in the past 10 years. In our laboratory, we conduct combinatorial mutagenesis at the active site of enzymes then select those with the properties that interest us, in a process known as ‘accelerated evolution’. We then perform detailed kinetic and biophysical characterization as well as computer-assisted molecular modelling, to identify modified enzymes that will serve as useful catalysts. A further important focus of our work is gaining insight into enzymes that cause drug resistance, with applications in the health sector. By this approach to enzyme modification and characterization, we will contribute to bridge the gap between disciplines such as Bio-Organic Chemistry, Biochemistry and Bio-informatics that are all essential to the further development of modern enzymology.


  • Fossati, E.  Volpato, J. P.,  Poulin, L.,  Guerrero, V.,  Dugas, D. A. et Pelletier, J. N. (2008) Two-tier in vivo and in vitro selection of active and methotrexate-resistant variants of human dihydrofolate reductase. Journal of Biomolecular Screening, 13(6) 504-514.
  • Volpato, J. P., Fossati, E. et Pelletier, J. N. (2007) Increasing methotrexate resistance by combination of active-site mutations in human dihydrofolate reductase. Journal of Molecular Biology, 373 (3), 599-611.
  • Doucet, N. et Pelletier, J.N. (2007) Simulated annealing exploration of an active-site tyrosine in TEM-1 beta-lactamase suggests the existence of alternate conformations. Proteins: Structure, Function and Bioinformatics, 69, 340–348.
  • Pelletier, J.N. et Lortie, R. (2007) Sequence-activity relationships guide directed evolution. Nature Biotechnology, 25 (3), 297- 298.