title: Constant helical pitch of the gramicidin channel in phospholipid bilayers.
abstract: X-ray diffraction has been applied in measuring the helical pitch of the gramicidin channel in oriented bilayers of dilauroylphosphatidylcholine (DLPC) and dimyristoylphosphatidylcholine (DMPC) at a polypeptide concentration of 9.1 mol %. The diffraction data show the helical pitch of gramicidin to be 4.7 +/- 0.2 A in both gel and liquid-crystalline phase bilayers, with and without monovalent cations. In addition, the width of the reflection due to the pitch of the helical gramicidin channel is consistent with a five turn helix.
authors.affiliation: Department of Physics, University of Guelph, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Katsaras
authors.forename: R S
authors.initials: RS
authors.lastname: Prosser
authors.forename: R H
authors.initials: RH
authors.lastname: Stinson
authors.forename: J H
authors.initials: JH
authors.lastname: Davis
mesh_terms: D004134:Dimyristoylphosphatidylcholine; D006096:Gramicidin / Q000737:chemistry*; D007473:Ion Channels; D008051:Lipid Bilayers; D008954:Models, Biological; D010713:Phosphatidylcholines; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D006096:Gramicidin; C015153:1,2-dilauroylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine