In vitro selection of a peptide aptamer that changes fluorescence in response to verotoxin.

A peptide aptamer that changes fluorescence upon binding to verotoxin was selected in vitro using ribosome display with a tRNA carrying an environment-sensitive fluorescent probe. The aptamer specifically bound to verotoxin with a dissociation constant (K d) of 3.94 ± 1.6 µM, and the fluorescence decreased by 78% as the verotoxin concentration was increased. The selected peptide can be used for detection of verotoxin.