title: Dynamic properties of the colicin E1 ion channel.
abstract: The mechanism of channel formation and action of channel-forming colicins is a paradigm for the study of dynamic aspects of membrane-protein interactions. The following experimental results concerning interaction of the colicin E1 channel domain with target membranes, in vitro and in vivo, are discussed: (1) the nature of the translocation-competent state of the channel-forming domain; (2) unfolding of the colicin channel peptide during in vitro binding and anchoring of the channel to liposome membranes at acidic pH; (3) reversal of channel peptide binding to liposomes by an alkaline-directed pH shift; (4) voltage-driven translocation and gating of the ion channel, discussed in the context of a four-helix model for a monomeric channel; (5) rescue of colicin-treated cells by high levels of external K+; (6) trypsin rescue of cells depolarized by the colicin ion channel; and (7) interaction of the channel domain with its immunity protein.
authors.affiliation: Department of Biological Sciences, Lilly Hall of Life Sciences, Purdue University, West Lafayette, IN.
authors.forename: W A
authors.initials: WA
authors.lastname: Cramer
authors.forename: Y L
authors.initials: YL
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Schendel
authors.forename: A R
authors.initials: AR
authors.lastname: Merrill
authors.forename: H Y
authors.initials: HY
authors.lastname: Song
authors.forename: C V
authors.initials: CV
authors.lastname: Stauffacher
authors.forename: F S
authors.initials: FS
authors.lastname: Cohen
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D003087:Colicins / Q000737:chemistry* / Q000633:toxicity; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000187:drug effects*; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D011188:Potassium / Q000494:pharmacology; D011487:Protein Conformation
chemical_list: D003087:Colicins; D007473:Ion Channels; D008565:Membrane Proteins; D011188:Potassium