title: Anion Transport in Liposomes Responds to Variations in the Anchor Chains and the Fourth Amino Acid of Heptapeptide Ion Channels.
abstract: Seven heptapeptide derivatives have been prepared. The peptide structure is (Gly)(3)Xxx(Gly)(3) in which Xxx stands for a variable amino acid. The amino acid variations include azetidine carboxylic acid, pipecolic acid, meta-aminobenzoic acid, proline, and leucine. All seven compounds have a C-terminal benzyl group. In all cases, the heptapeptide's N-terminus was linked to diglycolic acid and a dialkylamine. In five cases, the N-terminal group was didecylamine and in two cases, N-ethyl-N-decyl. Chloride and carboxyfluorescein release from phospholipid vesicles was studied with the result that C(10)H(21)N(C(2)H(5)) COCH(2)OCH(2)CO-NH-(Gly)(3)Leu(Gly)(3)-OCH(2)Ph was the most active. Hill analysis showed that this compound involves pore formation by four monomer units rather than two, as previously found for other members of this family.
authors.affiliation: Department of Molecular Biology & Pharmacology, Washington University School of Medicine, 660 South Euclid Ave., Campus Box 8103, St. Louis, MO 63110 USA.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ferdani
authors.forename: Robert
authors.initials: R
authors.lastname: Pajewski
authors.forename: Natasha
authors.initials: N
authors.lastname: Djedovič
authors.forename: Jolanta
authors.initials: J
authors.lastname: Pajewska
authors.forename: Paul H
authors.initials: PH
authors.lastname: Schlesinger
authors.forename: George W
authors.initials: GW
authors.lastname: Gokel