Light-emitting self-assembled peptide nucleic acids exhibit both stacking interactions and Watson-Crick base pairing

Area of Science:

• Bionanotechnology
• Supramolecular chemistry
• Materials science

Background:

• Bionanotechnology commonly utilizes peptide or DNA self-assembly.
• Peptide scaffolds offer versatility but lack DNA's precise molecular recognition.
• Peptide nucleic acids (PNAs) are DNA mimics with amide backbones, combining features of both.

Purpose of the Study:

• To investigate the self-assembly of short peptide nucleic acid (PNA) building blocks.
• To explore the structural and optical properties of PNA assemblies.

Main Methods:

• Synthesis of all 16 di-PNA combinations.
• Assay of self-assembly capabilities.
• Characterization by electron microscopy and X-ray crystallography.
• Analysis of optical properties.

Main Results:

• Three guanine-containing di-PNAs (CG, GC, GG) self-assembled into ordered nanostructures.
• Assemblies formed rapidly (minutes) into discrete architectures.
• X-ray structure revealed stacking and Watson-Crick base pairing in GC di-PNA.
• Assemblies exhibited voltage-dependent electroluminescence and fluorescence.

Conclusions:

• Short di-PNAs can self-assemble into ordered nanostructures.
• PNA assemblies possess unique optical properties, suggesting potential applications in optoelectronics.
• PNA self-assembly offers a novel route in bionanotechnology.