What Happens When Monopeptides Assemble?

Self-assembly is a ubiquitous phenomenon in Nature, resulting in the formation of an organized structure or pattern from disordered components via non-covalent interactions. Well-known examples include DNA double helix and protein quaternary structures. Differing from these large polymeric structures, in recent years we have been interested in designing easily manipulable and diversely functionalizable self-assembly from readily accessible extremely simple building blocks. More specifically, we focus our efforts on single amino acid-based monopeptides, carrying built-in H-bonding donors and acceptors that are capable of assembling into a well-defined one-dimensional columnar structure. This H-bonded highly ordered structure is characterized by (1) high reliability, i.e., formation of 1D structure is mostly independent of the side chains, (2) high tunability, i.e., structures are highly and finely tunable for rapid combinatorial optimization of desired outcomes, and (3) high directionality, i.e., the same type of side chains are always packed to the same side. These features have combined to give rise to many excellent phase-selective organogelators for oceanic oil spill treatment and highly active synthetic channels for selective transports of potassium ions, anions or protons. The medicinally relevant applications in promoting hair growth using potassium channels and anticancer treatment using chloride/proton channels also will be briefly discussed.