Pseudopeptosomes: non-lipidated vesicular assemblies from bispidine-appended pseudopeptides.

Area of Science:

• Biochemistry
• Materials Science
• Synthetic Biology

Background:

• Traditional amphiphiles rely on polar head and hydrophobic tail structures.
• Vesicular assemblies are crucial in biological systems and synthetic applications.
• Designing novel self-assembling molecules remains a key challenge.

Purpose of the Study:

• To develop a novel molecular topology-based approach for creating reproducible vesicular assemblies.
• To investigate the self-assembly of specifically designed pseudopeptides into vesicles.
• To characterize these novel vesicular structures, termed "pseudopetosomes".

Main Methods:

• Synthesis of specifically designed pseudopeptides.
• Characterization using high-resolution microscopy (SEM, TEM, AFM, epifluorescence, confocal) and dynamic light scattering.
• Spectroscopic analysis (FTIR, fluorescence) and molecular characterization (X-ray crystallography, circular dichroism) to probe interactions and structure.

Main Results:

• Successfully synthesized pseudopeptides self-assembled into reproducible vesicular structures ("pseudopetosomes") in various solvents, including aqueous environments.
• Characterization revealed "tryptophan (Trp)-Zip" arrangements and/or hydrogen-bonded assemblies, dependent on pseudopeptide sequence and solvent.
• Pseudopetosome formation involves sheets transforming into vesicles, utilizing all four major weak interactions essential in biology.

Conclusions:

• A novel molecular topology-based method enables the creation of reproducible pseudopetosomes.
• These pseudopetosomes have potential applications in chemical and synthetic biology, including cellular transport.
• The findings offer new insights into the origins of life through self-assembling systems.