The highly stabilized ribosome display selection of metal binding peptide aptamers.

Development of methods for in vitro selection of peptide aptamers with target binding affinities have been expected to construct biocatalysts, biosensors, and molecular targeted drugs in leading-edge fields of biotechnology and medical therapies. Therefore, a highly stabilized ribosome display method has been devised for efficient selection of various peptide aptamers from an artificial peptide library (APL). This ribosome display selection is performed by using a ribosomal conjugate consisted of APL, Cv RNA-associating protein (Cvap), and mRNA having Cv RNA motif at 5' terminus. The conjugate generated by in vitro translation can automatically link a peptide as phenotype and its mRNA as genotype, which can be stabilized by a high affinity association between Cv motif and Cvap. Here, in order to demonstrate the utility of this ribosome display method, we performed in vitro selection of peptide aptamers against a metal complex, and succeeded in identification and characterization of peptide aptamers with specific metal binding affinity. These results validate the concept to design APL in DNA level and indicate the versatility of the highly stabilized ribosome display selection.