title: Fusogenicity of Naja naja atra cardiotoxin-like basic protein on sphingomyelin vesicles containing oxidized phosphatidylcholine and cholesterol.
abstract: This study investigated the effect of oxidized phosphatidylcholine (oxPC) and cholesterol (Chol) on Naja naja atra cardiotoxin-like basic protein (CLBP)-induced fusion and leakage in sphingomyelin (SM) vesicles. Compared with those on PC/SM/Chol vesicles, CLBP showed a lower activity to induce membrane permeability but a higher fusogenicity on oxPC/SM/Chol vesicles. A reduction in inner-leaflet fusion elucidated that CLBP fusogenicity was not in parallel to its membrane-leakage activity on oxPC/SM/Chol vesicles. The lipid domain formed by Chol and SM supported CLBP fusogenicity on oxPC/SM/Chol vesicles, while oxPC altered the interacted mode of CLBP with oxPC/SM/Chol vesicles as evidenced by Fourier transform infrared spectra analyses and colorimetric phospholipid/polydiacetylene membrane assay. Although CLBP showed similar binding affinity with PC/SM/Chol and oxPC/SM/Chol vesicles, the binding capability of CLBP with PC/SM/Chol and oxPC/SM/Chol vesicles was affected differently by NaCl. This emphasized that CLBP adopted different membrane interaction modes upon binding with PC/SM/Chol and oxPC/SM/Chol vesicles. CLBP induced fusion in vesicles containing oxPC bearing the aldehyde group, and aldehyde scavenger methoxyamine abrogated the CLBP ability to induce oxPC/SM/Chol fusion. Taken together, our data indicate that Chol and oxPC bearing aldehyde group alter the CLBP membrane-binding mode, leading to fusogenicity promotion while reducing the membrane-damaging activity of CLBP.
authors: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
authors: Pei-Hsiu
authors: PH
authors: Kao
authors: Ying-Jung
authors: YJ
authors: Chen
authors: Shin-Yi
authors: SY
authors: Yang
authors: Shinne-Ren
authors: SR
authors: Lin
authors: Wan-Ping
authors: WP
authors: Hu
authors: Long-Sen
authors: LS
authors: Chang
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D002784:Cholesterol / Q000737:chemistry*; D004179:Cobra Cardiotoxin Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D017815:Elapidae / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008081:Liposomes / Q000737:chemistry; D008561:Membrane Fusion; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines / Q000737:chemistry*; D022142:Secretory Vesicles / Q000378:metabolism*; D013109:Sphingomyelins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004179:Cobra Cardiotoxin Proteins; D008081:Liposomes; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D002784:Cholesterol
keywords: cardiotoxin-like basic protein; cholesterol; fusogenic activity; membrane-bound mode; membrane-damaging activity; oxidized phospholipid