1.D.221.  The OctiPhenyl-Beta Barrel (OP-BB) Family 

Channel formation of p-octiphenyl β-barrels (41) with internal carboxylate groups reported by Matile and co-workers occurs at pH 6 (see figure below). The channel is formed via hydrogen bonding between the pendant peptide chains (Das and Matile 2002).  The transport efficiency of these channels is dictated by the protonation state of the carboxylate group (Kumar and Madhavan 2023).


Schematic representation of the channel or β-barrels formed via H-bonding between peptide chains of p-octiphenyl compound 41.

 

References:

Das, G. and S. Matile. (2002). Transmembrane pores formed by synthetic p-octiphenyl β-barrels with internal carboxylate clusters: regulation of ion transport by pH and Mg2+- complexed 8-aminonaphthalene-1,3,6-trisulfonate. Proc. Natl. Acad. Sci. USA 99: 5183-5188.
Kumar, N. and N. Madhavan. (2023). Small molecule-derived pH-gated ion transporters. Org Biomol Chem. [Epub: Ahead of Print]