Self-assembled dipeptide nanostructures of different chirality: an overview

Chirality is a property of an object to be non-superimposable on its mirror image. This simple, but the universal property of matter can be observed at various hierarchical levels from subatomic, molecular, and supramolecular to macro- and megascopic scales. An interest in chirality arises first from its ubiquitous presence in living matter. A huge number of chiral molecules such as amino acids (AA), sugars, etc. exist in nature and play a crucial role in living organisms.

Self-assembly of complex molecular structures based on AA is one of the most important phenomena both in living nature and in artificial biomimetics. At the same time, the chirality of the initial molecules also plays an important role in self-assembly processes. All this is important both for our understanding of wildlife and the basic principles of the emergence of life and for numerous practical applications. Self-organized macromolecules tend to form hierarchical structures with an alternation of the sign of chirality in the transition to a higher hierarchical level. Depending on the conformation of the primary structure (L or D), the properties of the material also change. Exemplifying such self-assembled macromolecules are peptide nanotubes (PNTs) based on various amino acids and their dipeptides. Due to their wide-ranging physical properties, PNTs are not only important in the study of biomolecular self-organization, but also show promise in various applications in the nanotechnological and biomedical fields. One example of such self-organizing macromolecules is diphenylalanine (FF) peptide nanotubes.

In this work, we will discuss the experimental and theoretical study of the structure and growth kinetics of L-FF and D-FF microtubes. Better understanding the role of chirality in the growth process will allow improving the methods for NTs and MTs fabrication, their better implementation in various functional devices, and may assist in developing new drugs and biomaterials.