1.D.95. The Synthetic Alpha-Helical Ion-conducting Barrel (SAHIB) Family
The fabrication of monodisperse transmembrane barrels formed from short synthetic peptides must reflect the complexity of the interactions between peptides and lipids within the hydrophobic environment of a membrane. Mahendran et al. 2017 reported the formation of a transmembrane pore through the self-assembly of 35 amino acid α-helical peptides. The design of the peptides is based on the C-terminal D4 domain of the E. coli polysaccharide transporter Wza. By using single-channel current recording, they defined discrete assembly intermediates and showed that the pore is probably formed of an α-helical barrel that contains eight D4 peptides arranged in parallel. They also showed that the peptide pore is functional and capable of conducting ions and binding blockers. Such α-heliical barrels, engineered from peptides, may find applications in nanopore technologies such as single-molecule sensing and nucleic-acid sequencing (Mahendran et al. 2017). This family is related to the pores later published and reported in TC family 1.D.158.