1joh
From Proteopedia
THE STRUCTURE OF ANTIAMOEBIN I, A MEMBRANE-ACTIVE PEPTIDE
Overview
BACKGROUND: Antiamoebin is a member of the peptaibol family of polypeptides and has a unique antibiotic activity: it acts as an antiamoebic agent, but does not effectively haemolyze erythrocytes even though it does exhibit membrane-modifying activity. RESULTS: The structure of antiamoebin I has been determined by X-ray crystallography at 1.4 A resolution. The molecule forms a helical structure, which, as a result of the presence of a number of proline and hydroxyproline residues, has a deep bend in the middle. Circular dichroism spectroscopy, single-channel conductance studies and fluorescence diffusion studies suggest a mode of ion transport that is entirely different from that of the other two members of the peptaibol family (alamethicin and zervamicin) whose structures and functions have been examined in detail. CONCLUSIONS: The structure of the polypeptide has been determined and a functional model for its mode of action in membranes is presented. Although under some conditions antiamoebin may form ion channels, unlike the closely related alamethicin and zervamicin polypeptides, its major membrane-modifying activity appears to be as an ion carrier.
About this Structure
Full crystallographic information is available from OCA.
Reference
The structure and function of antiamoebin I, a proline-rich membrane-active polypeptide., Snook CF, Woolley GA, Oliva G, Pattabhi V, Wood SF, Blundell TL, Wallace BA, Structure. 1998 Jun 15;6(6):783-92. PMID:9655831 Page seeded by OCA on Fri May 2 21:30:31 2008
