title: Zervamicins, a structurally characterised peptide model for membrane ion channels.
abstract: Voltage dependent membrane channels are formed by the zervamicins, a group of alpha-aminoisobutyric acid containing peptides. The role of polar residues like Thr, Gln and Hyp in promoting helical bundle formation is established by dramatically reduced channel lifetimes for a synthetic apolar analog. Crystal structures of Leu1-zervamicin reveal association of bent helices. Polar contacts between convex faces result in an 'hour glass' like arrangement of an aqueous channel with a central constriction. The structure suggests that gating mechanisms may involve movement of the Gln11 carboxamide group. Gln3 may play a role in modulating the size of the channel mouth.
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore.
authors.forename: S
authors.initials: S
authors.lastname: Agarwalla
authors.forename: I R
authors.initials: IR
authors.lastname: Mellor
authors.forename: M S
authors.initials: MS
authors.lastname: Sansom
authors.forename: I L
authors.initials: IL
authors.lastname: Karle
authors.forename: J L
authors.initials: JL
authors.lastname: Flippen-Anderson
authors.forename: K
authors.initials: K
authors.lastname: Uma
authors.forename: K
authors.initials: K
authors.lastname: Krishna
authors.forename: M
authors.initials: M
authors.lastname: Sukumar
authors.forename: P
authors.initials: P
authors.lastname: Balaram
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D004553:Electric Conductivity; D007473:Ion Channels / Q000502:physiology*; D008051:Lipid Bilayers; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D054848:Peptaibols; D010455:Peptides / Q000737:chemistry; D010713:Phosphatidylcholines; D011487:Protein Conformation
chemical_list: D000900:Anti-Bacterial Agents; D007473:Ion Channels; D008051:Lipid Bilayers; D054848:Peptaibols; D010455:Peptides; D010713:Phosphatidylcholines; C069342:zervamicin Z-L; C021016:1,2-diphytanoylphosphatidylcholine