Template-free self-assembling fullerene and lipopeptide conjugates of alamethicin form voltage-dependent ion channels of remarkable stability and activity.
N- and C-terminally modified with fullerene or lipopeptide alamethicin molecules were designed for the formation of template-free, self-assembling, voltage-dependent ion conducting channels. The automated solid phase synthesis of the alamethicin-F30 sequence was performed by in situ fluoride activation on 2-chlorotritylchloride-polystyrene resin and the conjugation with fullerenes-C60 and -C70 was carried out in solution. Voltage-dependent bilayer experiments revealed preferred channel sizes for C-terminal alamethicin F30-fullerene-C60 and -C70 conjugates and higher activity compared with native alamethicin, whereas N-terminally linked fullerene balls destabilize pore formation. C-terminal alamethicin F30-fullerene-C70 conjugates show pore states with remarkably long lifetimes of seconds. C-terminal lipopeptide conjugates of alamethicin were prepared by coupling via short peptide spacers with synthetic tripalmitoyl-S-glyceryl-cysteine. which represents the strong membrane anchoring N-terminus of bacterial lipoprotein. Alamethicin-lipopeptide conjugates exhibit high channel forming activities, whereby they self-assemble and adopt preferred pore states with extremely long lifetimes. The novel membrane modifying peptaibol constructs are valuable lead compounds for developments in sensorics related to transmembrane ion conductance.
Jung
Günther
G
Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany. guenther.jung@uni-tuebingen.de
Redemann
Thomas
T
Kroll
Karsten
K
Meder
Sabine
S
Hirsch
Andreas
A
Boheim
Günther
G
D000408:Alamethicin / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004355:Drug Stability; D004594:Electrophysiology; D037741:Fullerenes / Q000737:chemistry*; D007473:Ion Channels / Q000138:chemical synthesis*; D008051:Lipid Bilayers; D008074:Lipoproteins / Q000737:chemistry*; D018716:Molecular Mimicry
D003432:Cross-Linking Reagents; D037741:Fullerenes; D007473:Ion Channels; D008051:Lipid Bilayers; D008074:Lipoproteins; C069836:fullerene C70; D000408:Alamethicin; C069837:fullerene C60