Antiamoebin can function as a carrier or as a pore-forming peptaibol.
Antiamoebin is a 16-residue polypeptide whose crystal structure and lytic activity in membrane vesicles have recently been reported. It is a bent helical molecule and a member of the peptaibol family of antibiotics. Under conditions which produce voltage-dependent conductance activity by other members of the family, no single-channel conductance was detected for antiamoebin, and a carrier-like mechanism was put forward to account for its mode of action. We now present evidence for pore formation that is largely voltage-insensitive, with large amplitude single-channel events on top of a background conductance that may account for the previously proposed carrier-like activity. Thus, antiamoebin may be the first instance of a peptide which can function both as an ion carrier and a pore former.
Duclohier
H
H
UMR 6522 CNRS-Université de Rouen (IFRMP 23), Boulevard M. de Broglie, 76821 Mont-Saint-Aignan, France. Herve.Duclohier@univ-rouen.fr
Snook
C F
CF
Wallace
B A
BA
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D015640:Ion Channel Gating; D008051:Lipid Bilayers / Q000378:metabolism; D008969:Molecular Sequence Data; D054848:Peptaibols; D010455:Peptides
D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D008051:Lipid Bilayers; D054848:Peptaibols; D010455:Peptides; C006596:antiamoebin