ToF-SIMS observation for evaluating the interaction between amyloid β and lipid membranes

• Published in: Analytical and bioanalytical chemistry Vol. 407; no. 10; pp. 2859 - 2863
• Main Authors: Aoyagi, Satoka, Shimanouchi, Toshinori, Kawashima, Tomoko, Iwai, Hideo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2015
• Subjects: 1,2-Dipalmitoylphosphatidylcholine - analogs & derivatives; 1,2-Dipalmitoylphosphatidylcholine - chemistry; Aggregates; Alzheimer's disease; Amino Acid Sequence; Amyloid beta-Peptides - chemistry; Amyloid beta-Peptides - metabolism; Analytical Chemistry; Biochemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Clusters; Data processing; Dimyristoylphosphatidylcholine - chemistry; Food Science; Glycerylphosphorylcholine - analogs & derivatives; Glycerylphosphorylcholine - chemistry; Image Processing, Computer-Assisted; Ion beams; Laboratory Medicine; Lipids; Mathematical analysis; Membrane Lipids - chemistry; Membrane Lipids - metabolism; Membranes; Molecular Sequence Data; Monitoring/Environmental Analysis; Peptides; Phosphatidylcholines; Principal Component Analysis; Research Paper; Spectrometry, Mass, Secondary Ion - methods; Ar cluster beam; Amyloid beta; Peptide structure; ToF-SIMS; Lipid
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-015-8527-3

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, Bi 3 + 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.