Design, synthesis and binding properties of the PNA-peptide hybrid for organic nanostructures

Abstract

Two- and three-dimensional nanostructures incorporating biopolymers, such as nucleic acid, and peptides are currently under active investigation. Related medical application of these nanostructures includes targeted drug and gene delivery, for which issues relating to the exhibition and the control of specific properties inside the cell. In routine fabrications, biopolymers are usually encapsulated in a spherical or sphere-like structure or bound to a nanostructure surface. Nevertheless, modulation of the nanostructure via the assembly and disassembly of itself has never been fully examined. We designed a structure-controllable building block in this respect, PNA-peptide hybrid, of which the nanostructure was formed by peptide-peptide interactions first and the recursive formation and disintegration of the corresponding secondary structure were induced by manipulating the binding affinity of PNA. The PNA-$\Beta$-sheet peptide hybrid structure is especially found to form secondary structure itself of the dot, or sphere shape and by the co-assembly with peptides the nanofiber is then formed. Interestingly, the structure of the nanofiber could be controlled by specific concentrations of the complementary nucleic acid. Utilizing such characteristics, various applications of the hybrid structure in many fields are expected.