Constant helical pitch of the gramicidin channel in phospholipid bilayers.
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.
Katsaras
J
J
Department of Physics, University of Guelph, Ontario, Canada.
Prosser
R S
RS
Stinson
R H
RH
Davis
J H
JH
D004134:Dimyristoylphosphatidylcholine; D006096:Gramicidin / Q000737:chemistry*; D007473:Ion Channels; D008051:Lipid Bilayers; D008954:Models, Biological; D010713:Phosphatidylcholines; D011487:Protein Conformation; D014961:X-Ray Diffraction
D007473:Ion Channels; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D006096:Gramicidin; C015153:1,2-dilauroylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine