Vescovi Andrea, Knoll Andrea, Koert Ulrich
Institut für Chemie, Humboldt-Universität Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany.
Org Biomol Chem. 2003 Aug 21;1(16):2983-97. doi: 10.1039/b303249n.
THF-gramicidin hybrids 2-4 with the L-THF amino acid 1 in positions 11 and 12 and compounds 5-8 with the D-THF amino acid ent-1 in positions 10 and 11 were synthesized and their ion channel properties were studied by single-channel-current analysis. The replacement of positions 11 and 12 by the L-THF amino acid 1 gave a strongly reduced channel performance. In contrast, replacement of positions 10 and 11 by the D-THF amino acid ent-1 gave rise to new and interesting channel properties. For the permeability ratios, the ion selectivity shifts from Eisenman I towards Eisenman III selectivity and the channels display ms-dynamics. Most remarkable is the asymmetric compound 8, which inserts selectively into a DPhPC membrane and displays voltage-directed gating dynamics.
