The Chemical Repertoire of DNA Enzymes
Résumé
Catalytic DNA molecules (DNAzymes) have joined the ranks of biopolymers capable of catalyzing chemical transformations. Unlike their RNA and protein counterparts, naturally occurring DNAzymes have never been identified and are man-made molecules obtained by a Darwinian in vitro evolution method coined SELEX (Systematic Evolution of Ligands by Exponential Enrichment). This chapter introduces the reader to the world of DNAzymes and describes their catalytic repertoire and highlights their usefulness in numerous practical applications such as gene therapy or metal biosensing. This chapter also presents mechanistic and structural insights into the modus operandi of these biocatalysts. Despite their intrinsic properties, DNAzymes present some shortcomings including poor cellular uptake, low residence times and poor pharmacokinetic properties, and limited access to functional groups to mediate catalysis. Hence, a last section of this chapter is dedicated to discussing the introduction of chemical modifications into the scaffold of DNAzymes to alleviate these limitations.