1.D.195. The α-Helical D-Amino Acid Pore-forming (D-PORE) Family
Krishnan R et al. 2022 presented a transmembrane pore DpPorA, based on the natural pore PorACj, built from D-amino acid alpha-helical peptides. Using single-channel current recordings, they showed that DpPorA peptides self-assemble into uniform cation-selective pores in lipid membranes and exhibit properties distinct from their L-amino acid counterparts. DpPorA shows resistance to proteases and acts as a functional nanopore sensor to detect cyclic sugars, polypeptides, and polymers. Fluorescence imaging revealed that DpPorA forms well-defined pores in giant unilamellar vesicles, facilitating the transport of hydrophilic molecules. A second D-amino acid peptide based on the polysaccharide transporter Wza forms transient pores, confirming sequence specificity in stable, functional pore formation. Molecular dynamics simulations revealed the specific α-helical packing and surface charge conformation of the D-pores. These findings may aid the design of sophisticated pores for single-molecule sensing related technologies (Krishnan R et al. 2022).