Terminal Is Important for the Helicity of the Self-Assemblies of Dipeptides Derived from Alanine

Abstract

The organization of peptides and proteins attracts much attention, due to the biofunctionalities of the self-assemblies. Herein, four dipeptides derived from alanine were synthesized. It was found that the handedness of their self-assemblies was controlled by the chirality of the alanines at the terminals. The organic self-assemblies were studied using circular dichroism, (1)H NMR, Fourier transform infrared, field-emission electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicated that the electrostatic interactions among the carboxylate groups and H-bondings among the amide groups at the terminals play important roles in the formation of the organic self-assemblies.

Supramolecular Chirality in Self-Assembled Systems

“…Remarkably, homochiral LL and DD peptide-modified NDIs self-assembled into 1D hierarchical supramolecular polymers with opposite helicity, while the heterochiral peptide conjugates LD and DL formed microspheres. 141 Yang et al 142 reported an interesting control of handedness of the alanine dipeptide self-assemblies by the chirality of the were right-handed. The morphologies of the assemblies were consistent with the CD spectral data, which also indicated that the handedness of these organic selfassemblies was controlled by the chirality of the alanines at the terminals.…”

The Unexpected Advantages of Using D-Amino Acids for Peptide Self- Assembly into Nanostructured Hydrogels for Medicine

“…3 ). This work showed that the chirality of the C -terminal amino acid dictates the chiral orientation of the supramolecular helical nanoribbons, with on one hand the L Ala- D Ala derivative having the same handedness as the D Ala- D Ala counterpart, and on the other hand the D Ala- L Ala derivative having the same handedness as the L Ala- L Ala analogue [38]. …”

Glutathione-Triggered Formation of a Fmoc-Protected Short Peptide-Based Supramolecular Hydrogel

“…They were longer than 2 µm and entangled with each other to form 3D networks for hydrogel formation. The examples of helical nanofibers in hydrogels were rare [51]–[55], and the helical nanofibers in this hydrogel might be useful as templates for the preparation of helical organic and in-organic nano-materials.…”