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Updated: Apr 7, 2026

A Proteoliposome-Based Efflux Assay to Determine Single-molecule Properties of Cl- Channels and Transporters
Published on: April 20, 2015
Calixarene-Mediated Liquid-Membrane Transport of Choline Conjugates
Birendra Babu Adhikari1, Ayu Fujii1, Michael P Schramm1
1Department of Chemistry and Biochemistry, University Long Beach,, 1250 Bellflower Blvd., Long Beach, CA 90840, USA: http://schrammlab.wordpress.com.
Abstract:
A series of supramolecular calixarenes efficiently transport distinct molecular species through a liquid membrane when attached to a receptor-complementary choline handle. Calix-[6]arene hexacarboxylic acid was highly effective at transporting different target molecules against a pH gradient. Both carboxylic- and phosphonic-acid-functionalized calix[4]arenes effect transport without requiring a pH or ion gradient. NMR binding studies, two-phase solvent extraction, and three-phase transport experiments reveal the necessary and subtle parameters to effect the transport of molecules attached to a choline "handle". On the other hand, rescorin[4]arene cavitands, which have similar guest recognition profiles, did not transport guest molecules. These developments reveal new approaches towards attempting synthetic-receptor-mediated selective small-molecule transport in vesicular and cellular systems.
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