1.D.153. The Hetero-Oligomeric Peptidic Synthetic 3-in-1 Transporter (HOP-3in1T) Family
A crystal packing-inspired social self-sorting strategy broadly applicable to diverse types of H-bonded peptidic frameworks has been designed (Zeng et al. 2021). Specifically, a crystal structure of H-bonded alkyl chain-appended monopeptides revealed an inter-chain separation distance of 4.8 Å dictated by the H-bonded amide groups, which is larger than the 4.2 Å separation distance desired by tightly packed
straight alkyl chains. This incompatibility resulted in loosely packed alkyl chains, prompting an investigation of the feasibility of applying bulky tert-butyl groups, modified with an anion-binding group, to alternately interpenetrate the straight alkyl chains, modified with a crown ether group. Structurally, this social self-sorting approach generated highly stable hetero-oligomeric ensembles, having alternated anion- and cation-binding units vertically aligned to the same side. Functionally, these hetero-oligomeric ensembles promote transmembrane transport of cations, anions and more
interestingly, zwitterionic species such as amino acids (Zeng et al. 2021).