[Molecular evolution: creation of nucleic acids capable of specific complex formation and possessing catalytic functions].

Method of designing nucleic acids capable of specific complex formation with arbitrary ligands (aptamers) and catalytically competent nucleic acids are described. The methods rely on generation of libraries of random nucleotide sequences, selection of molecules possessing the desired property from these libraries, and amplification of the selected molecules. Repeating of the selection and amplification procedures results in evolutional improvement of the molecule ability to accomplish the function under consideration. This molecular evolution approach opens up broad possibilities for investigation of mechanisms of molecular recognition of small ligands and biopolymers by nucleic acids and mechanisms of reactions catalyzed by ribozymes. Design of novel ribozymes and nucleic acids capable of specific binding to certain biopolymers may become an efficient approach for development of practically important compounds, biologically active compounds and affinity sorbents.