title: Measurement of Hanatoxin-Induced Membrane Thinning with Lamellar X-ray Diffraction.
abstract: Membrane perturbation induced by cysteine-rich peptides is a crucial biological phenomenon but scarcely investigated, in particular with effective biophysical-chemical methodologies. Hanatoxin (HaTx), a 35-residue polypeptide from spider venom, works as an inhibitor of drk1 (Kv2.1) channels, most likely by interacting with the voltage-sensor. However, how this water-soluble peptide modifies the gating remains poorly understood, as the voltage sensor was proposed to be deeply embedded within the bilayer. To see how HaTx interacts with phospholipid bilayers, we observe the toxin-induced perturbation on POPC/DOPG-membranes through measurements of the change in membrane thickness. Lamellar X-ray diffraction (LXD) was applied on stacked planar bilayers in the near-fully hydrated state. The results provide quantitative evidence for the membrane thinning in a concentration-dependent manner, leading to novel and direct combinatory approaches by discovering how to investigate such a biologically relevant interaction between gating-modifier toxins and phospholipid bilayers.
authors.affiliation: Institute of Biotechnology, National Taiwan University , Taipei 10672, Taiwan.
authors.forename: Meng-Hsuan
authors.identifier: 0000-0003-1414-5975
authors.initials: MH
authors.lastname: Hsieh
authors.affiliation: Membrane Protein Research Core, Center for Biotechnology, National Taiwan University , Taipei 10672, Taiwan.
authors.forename: Yu-Shuan
authors.initials: YS
authors.lastname: Shiau
authors.affiliation: Division of Neurology, National Taiwan University Hospital , Taipei 10002, Taiwan.|Institute of Pharmacology, National Taiwan University , Taipei 10051, Taiwan.
authors.forename: Horng-Huei
authors.initials: HH
authors.lastname: Liou
authors.affiliation: National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan.
authors.forename: U-Ser
authors.identifier: 0000-0002-2247-5061
authors.initials: US
authors.lastname: Jeng
authors.affiliation: National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan.|Department of Physics, National Central University , Jhongli 32001, Taiwan.
authors.forename: Ming-Tao
authors.initials: MT
authors.lastname: Lee
authors.affiliation: Institute of Biotechnology, National Taiwan University , Taipei 10672, Taiwan.|Membrane Protein Research Core, Center for Biotechnology, National Taiwan University , Taipei 10672, Taiwan.
authors.forename: Kuo-Long
authors.initials: KL
authors.lastname: Lou
mesh_terms: D010455:Peptides / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D013111:Spider Venoms / Q000737:chemistry; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D010455:Peptides; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D013111:Spider Venoms; C096469:hanatoxin; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine