title: ToF-SIMS observation for evaluating the interaction between amyloid β and lipid membranes.
abstract: The adsorption behaviour of amyloid beta (Aβ), thought to be a key peptide for understanding Alzheimer's disease, was investigated by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS). Aβ aggregates depending on the lipid membrane condition though it has not been fully understood yet. In this study, Aβ samples on different lipid membranes, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), were observed with ToF-SIMS and the complex ToF-SIMS data of the Aβ samples was interpreted using data analysis techniques such as principal component analysis (PCA), gentle-SIMS (G-SIMS) and g-ogram. DOPC and DMPC are liquid crystal at room temperature, while DPPC is gel at room temperature. As primary ion beams, Bi3(+) and Ar cluster ion beams were used and the effect of an Ar cluster ion for evaluating biomolecules was also studied. The secondary ion images of the peptide fragment ions indicated by G-SIMS and g-ogram were consistent with the PCA results. It is suggested that Aβ is adsorbed homogeneously on the liquid-crystalline-phase lipid membranes, while it aggregates along the lipid on the gel-phase lipid membrane. Moreover, in the results using the Ar cluster, the influence of contamination was reduced.
authors: Department of Material and Life Science, Skeikei University, 3-3-1 Kichijoji-Kitamachi, Musashino-shi, Tokyo, 180-8633, Japan, aoyagi@st.seikei.ac.jp.
authors: Satoka
authors: S
authors: Aoyagi
authors: Toshinori
authors: T
authors: Shimanouchi
authors: Tomoko
authors: T
authors: Kawashima
authors: Hideo
authors: H
authors: Iwai
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D005997:Glycerylphosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010713:Phosphatidylcholines; D025341:Principal Component Analysis; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*
chemical_list: D016229:Amyloid beta-Peptides; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D015060:1,2-Dipalmitoylphosphatidylcholine; C081581:colfosceril palmitate; D005997:Glycerylphosphorylcholine; C017251:1,2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine