文摘
We coin the term "smart aptamers"-aptamers withpredefined binding parameters (kon, koff, Kd) of aptamer-target interaction. Aptamers, in general, are oligonucleotides, which are capable of binding target molecules withhigh affinity and selectivity. They are considered aspotential therapeutic targets and also thought to rivalantibodies in immunoassay-like analyses. Aptamers areselected from combinatorial libraries of oligonucleotidesby affinity methods. Until now, technological limitationshave precluded the development of smart aptamers. Here,we report on two kinetic capillary electrophoresis techniques applicable to the selection of smart aptamers.Equilibrium capillary electrophoresis of equilibrium mixtures was used to develop aptamers with predefinedequilibrium dissociation constants (Kd), while nonequilibrium capillary electrophoresis of equilibrium mixturesfacilitated selection of aptamers with different dissociationrate constants (koff). Selections were made for MutSprotein, for which aptamers have never been previouslydeveloped. Both theoretical and practical aspects of smartaptamer development are presented, and the advantagesof this new type of affinity probes are described.