Design and synthesis of an artificial ladder-shaped polyether that interacts with glycophorin A.

Ladder-shaped polyether (LSP) compounds, such as brevetoxins and ciguatoxins, are thought to interact with transmembrane (TM) proteins. As a model LSP compound, we designed and synthesized an artificial tetracyclic ether (1) and evaluated its interaction with glycophorin A (GpA), a membrane protein known to dimerize or oligomerize between membrane-integral alpha-helical domains. Model compound 1 was found to induce the dissociation of oligomeric GpA in a similar manner to natural LSPs when examined by SDS-PAGE. The results suggest that even an artificial tetracyclic ether possesses the ability to interact with TM proteins, presumably through the intermolecular hydrogen bonds (C(alpha)-Hcdots, three dots, centeredO) with the GXXXG motif.