The formation of helical tubular vesicles by binary monolayers containing a nickel-chelating lipid and phosphoinositides in the presence of basic polypeptides.
Binary lipid monolayers consisting of equimolar proportions of a phosphoinositide and a nickel-chelating lipid formed helical tubular vesicular structures, which appeared to be induced and/or stabilized by myelin basic protein (MBP). Another basic polypeptide, poly-L-lysine, had a similar effect but not to as great a degree as MBP; the proteins thus appeared to act as polycations. Although, the nickel-chelating lipid is a synthetic product, other endogenous divalent cations such as Zn(2+), as well as phosphoinositides, are integral and dynamic components of the myelin sheath in vivo. There, comparable helical tubular structures might represent a means for sequestration of these lipids into domains of high local concentration, perhaps in regions where the membrane is greatly curved.
Ishiyama
Noboru
N
Biophysics Interdepartmental Group, Department of Molecular Biology and Genetics, University of Guelph, 50 Stone Road East, Ont., N1G 2W1, Guelph, Canada.
Hill
Christopher M
CM
Bates
Ian R
IR
Harauz
George
G
D000818:Animals; D002614:Chelating Agents / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D051379:Mice; D008854:Microscopy, Electron; D004676:Myelin Basic Protein / Q000494:pharmacology*; D009186:Myelin Sheath / Q000737:chemistry; D009532:Nickel / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000737:chemistry* / Q000378:metabolism; D011107:Polylysine / Q000494:pharmacology
D002614:Chelating Agents; D008055:Lipids; D008567:Membranes, Artificial; D004676:Myelin Basic Protein; D010716:Phosphatidylinositols; D011107:Polylysine; D009532:Nickel