Zervamicins, a structurally characterised peptide model for membrane ion channels.
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.
Agarwalla
S
S
Molecular Biophysics Unit, Indian Institute of Science, Bangalore.
Mellor
I R
IR
Sansom
M S
MS
Karle
I L
IL
Flippen-Anderson
J L
JL
Uma
K
K
Krishna
K
K
Sukumar
M
M
Balaram
P
P
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
D000900:Anti-Bacterial Agents; D007473:Ion Channels; D008051:Lipid Bilayers; D054848:Peptaibols; D010455:Peptides; D010713:Phosphatidylcholines; C069342:zervamicin Z-L; C021016:1,2-diphytanoylphosphatidylcholine