Reducing Product Inhibition in DNA-Template-Controlled Ligation Reactions

摘要

Template-directed chemical reactions display features of enzymatic reactions.[1] The binding of reactants allows the alignment of reactive groups to facilitate conversions that would proceed less efficiently when performed in the absence of the template. Templated synthesis has frequently been applied in nucleic acid chemistry, in the construction of nanometer-sized architectures,[2] for the encoding of amplifiable small-molecule libraries,[3] in studies of molecular mechanisms of evolution,[4] to release drugs,[5] and as a diagnostic means of detecting the presence of the nucleic acid template.[6] In contrast to enzymatic reactions, particularly ligation reactions, templates rarely exhibit catalytic turnover since the product usually binds the template with higher affinity than the reactants did before ligation.[7] As a result, stoichiometric amounts of the template are required which is of concern in studies of chemical evolution and in strategies for DNA/RNA detection. Here, we present a potentially general approach to reduce product inhibition in template-controlled ligation reactions. We show that high turnover numbers can be achieved by means of a ligation-rearrangement sequence in which the rearrangement is designed to reduce the template affinity of the initially formed ligation product.