Tryptophan-PNA gc Conjugates Self-Assemble to Form Fibers

Peptide nucleic acids and their conjugates to peptidescan self-assembleand generate complex architectures. In this work, we explored theself-assembly of PNA dimers conjugated to the dipeptide WW. Our studiessuggest that the indole ring of tryptophan promotes aggregation ofthe conjugates. The onset of fluorescence is observed upon self-assembly.The structure of self-assembled WWgc is concentration-dependent, beingspherical at low concentrations and fibrous at high concentrations.As suggested by molecular modeling studies, fibers are stabilizedby stacking interactions between tryptophans and Watson-Crick hydrogenbonds between nucleobases.