西亚试剂：Measuring Single Small Molecule Binding via Rupture Forces

Measuring Single Small Molecule Binding via Rupture Forces of a Split Aptamer

Thi-Huong Nguyen12, Lorenz Jan Steinbock1, Hans-Jrgen Butt1, Mark Helm*2, and Rdiger Berger*1

The rupture force of a split (bipartite) aptamer that forms binding pockets for adenosine monophosphate (AMP) was measured by atomic force spectroscopy. Changes in the rupture force were observed in the presence of AMP, while this effect was absent when mutant aptamers or inosine were used. Thus, changes in the rupture force were a direct consequence of specific binding of AMP to the split aptamer. The split aptamer concept allowed the detection of nonlabeled AMP and enabled us to determine the dissociation constant on a single-molecule level.