Solvent-controlled self-assembly of Fmoc protected aliphatic amino acids

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Modified amino acids, particularly Fmoc-protected single amino acids (Fmoc-SAAs), are valuable for creating functional materials due to their self-assembly properties.
• The ease of synthesis and potential for broad adoption make Fmoc-SAAs attractive building blocks for novel structures.
• Controlling the self-assembly of these smaller units is key to designing diverse bio-organic scaffolds.

Purpose of the Study:

• To demonstrate the controlled self-assembly of Fmoc-protected aliphatic single amino acids (Fmoc-SAAs) into distinct micro/nanostructures.
• To investigate the influence of environmental parameters, specifically solvent variation, on the resulting morphologies.
• To elucidate the underlying mechanisms governing these morphological transitions.

Main Methods:

• Synthesis and self-assembly of Fmoc-protected Alanine, Valine, Leucine, Isoleucine, and Proline.
• Systematic variation of solvents to induce and control morphological changes.
• Coarse-grained molecular dynamics simulations to investigate the self-assembly mechanisms.

Main Results:

• Controlled morphological transitions were achieved by varying solvents for Fmoc-SAAs.
• Fmoc-Alanine (FmocA) formed well-defined crystalline structures via parallel Fmoc stacking, influenced by ion concentrations.
• Other Fmoc-SAAs did not exhibit the same degree of controlled crystalline formation under similar conditions.
• The study highlights the tunability of Fmoc-SAA self-assembly through environmental parameter control.

Conclusions:

• Fmoc-protected aliphatic single amino acids serve as novel scaffolds for designing diverse micro/nanostructures.
• A bottom-up approach, tunable by environmental parameters like solvent and ion concentration, enables precise control over self-assembly.
• These findings open avenues for developing advanced functional materials based on amino acid self-assembly.