Virus-like supramolecular assemblies formed by cooperation of base pairing interaction and peptidic association

Abstract

A peptide nucleic acid (PNA)-peptide conjugated molecule, T′3(AKAE)2, was designed to have both a PNA segment for oligonucleotide binding and an ionic self-complementary peptide sequence for self-association. T′3(AKAE)2 could co-assemble with oligoadenines (d(A) x ) to form virus-like supramolecular structures whose morphology showed dependence on the chain length and rigidity of the d(A) x molecules. Smaller nanospheres with diameters of 13.0±2.0 nm were produced in the case of d(A)6. Wormlike aggregates with lengths of 20–50 nm and diameters of 15.0±2.5 nm were found in the cases of d(A)12, d(A)18, d(A)24 and d(A)30. And larger spherical aggregates with diameters of 18±5 nm came into presence in the cases of d(A)36 and d(A)42. These nanostructures were suggested to be formed under a cooperative effect of base pair recognition and peptidic association. The study provides insights into the programmed assembly of a multi-components system as well as control of the size and shape of the co-assembled structures, which is of great significance in developing gene/drug delivery systems.