Abstract
Anselme Payen is credited with the discovery of enzymes in the 19th century[1]. He also coined the term " cellulose "[2], so the existence of cellulose-degrading enzymes (cellulases) could already be imagined at that time. Enzymes that deconstruct glycoconjugates, oligo- and polysaccharides were characterized very early on (e.g. invertase[3]), and lysozyme was the first enzyme whose three-dimensional structure was resolved by radiocrystallography[4]. With advances in the study of their catalytic mechanisms[5], the mid-twentieth century saw the advent (and some would say the apogee) of enzymology. The discovery of new glycosidic bond-cutting enzymes then accelerated (and became commonplace) thanks to methodological advances : molecular biology and structural biology. Bioinformatics then helped to propose a new classification of these enzymes based not on their substrate but on their sequence[6], correlated with both structure and catalytic mechanism[7], and preceding - fortunately - the deluge of sequences from genome sequencing. These developments have rationalized research efforts in the field, and have accompanied the application of these enzymes in numerous fields : agrifood, paper, healthcare, biotechnology, biofuels and green chemistry.
After more than a century of discoveries and the transition to the post-genomic era, it is legitimate to ask about the discovery potential of this field of research with its particularly rich history. This seminar showed that, surprisingly, despite the progress of the past, the study of enzymes catalyzing the cleavage of glycosidic bonds is still a particularly fertile field in the 21st century, with the regular discovery of new families, new substrates and new reactions. Instead of levelling off, the number of new discoveries continues to rise with no sign of abating, gradually revealing the unsuspected importance of complex sugars throughout the biosphere. We will discuss the latest methods developed to explore the functional diversity of these enzymes, as well as the intrinsic reasons behind this diversity.
References
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