Orientation and pore-forming mechanism of a scorpion pore-forming peptide bound to magnetically oriented lipid bilayers.
The orientation and pore-forming mechanisms of pandinin 2 (pin2), an antimicrobial peptide isolated from venom of the African scorpion Pandinus imperator, bound to magnetically oriented lipid bilayers were examined by 31P and 13C solid-state, and 15N liquid-state NMR spectroscopy. 31P NMR measurements at various temperatures, under neutral and acidic conditions, showed that membrane lysis occurred only under acidic conditions, and at temperatures below the liquid crystal-gel phase transition of the lipid bilayers, after incubation for two days in the magnet. Differential scanning calorimetry measurements showed that pin2 induced negative curvature strain in lipid bilayers. The 13C chemical shift values of synthetic pin2 labeled at Gly3, Gly8, Leu12, Phe17, or Ser18 under static or slow magic-angle spinning conditions, indicate that pin2 penetrates the membrane with its average helical axis perpendicular to the membrane surface. Furthermore, amide H-D exchange experiments of 15N-Ala4, Gly8, and Ala9 triply-labeled pin2 suggest that this peptide forms oligomers and confirms that the N-terminal region creates membrane pores.
Suntory Institute for Bioorganic Research, Osaka 618-8503, Japan. nomura@sunbor.or.jp.
Kaoru
K
Nomura
Gerardo
G
Corzo
Terumi
T
Nakajima
Takashi
T
Iwashita
D001665:Binding Sites / Q000528:radiation effects; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D004574:Electromagnetic Fields; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry* / Q000528:radiation effects*; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008560:Membrane Fluidity / Q000528:radiation effects*; D008567:Membranes, Artificial; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry*; D044367:Phase Transition; D010715:Phosphatidylglycerols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D016062:Porosity / Q000528:radiation effects; D011485:Protein Binding / Q000528:radiation effects; D011487:Protein Conformation / Q000528:radiation effects; D017433:Protein Structure, Secondary / Q000528:radiation effects; D012604:Scorpion Venoms / Q000737:chemistry*; D013696:Temperature
D008051:Lipid Bilayers; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D010455:Peptides; D010715:Phosphatidylglycerols; D010743:Phospholipids; D012604:Scorpion Venoms; C476118:pandinin 2; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine