[Abstract Title]. - Society for Neuroscience

characterized forms of labeled Aβ42 oligomers. As researchers become increasingly
conscientious of utilizing structurally uniform, well-characterized Aβ preparations, the same
criteria must be imposed on derivitized Aβ assemblies such as fluorophore-labeled- and biotinlabeled-Aβ,
prior to their widespread use as experimental tools. Therefore, the objective of this
study is to obtain and characterize uniform preparations of fluorescently-labeled Aβ42 oligomers
that are comparable to the unlabeled species in both structure and function. Previous studies have
demonstrated the advantages of using tapping mode atomic force microscopy (AFM) to
characterize the structurally discreet species formed by synthetic Aβ42 under specific solution
conditions (e.g., oligomers, protofibrils and fibrils). Here, we extend these methods to
characterize the effects of fluorophore conjugation on Aβ assembly state and to ensure
fluorophore-labeled oligomers remain as uniform assemblies, free from fibrils, protofibrils or
other conformations of the peptide. Finally, we compare the function of fluorophore-labeled- and
unlabeled oligomeric Aβ42 by monitoring neurotoxicity and cellular uptake in neuronal cells.
AFM-characterized fluorophore-Aβ42 oligomers are an exciting new reagent for use in a variety
of studies designed to elucidate critical cellular and molecular mechanisms underlying the
toxicity of this Aβ assembly form in AD.
Disclosures: L.M. Jungbauer, None; C. Yu, None; M. LaDu, None.
Poster
243. Abeta Assembly and Deposition
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 243.15/L5
Topic: C.01.b. Abeta assembly and deposition
Support: grants-in-aid for Scientific Research A (No.18208011) from Japanese Government
Title: Verification of the intermolecular parallel β-sheet in E22K-Aβ42 (Italian) aggregates by
solid-state NMR using rotational resonance: Implications for the supramolecular arrangement of
the toxic conformer of Aβ42
Authors: *K. IRIE 1 , Y. MASUDA 1 , A. NAKANISHI 2 , R. OHASHI 2 , K. TAKEGOSHI 2 , T.
SHIMIZU 3 , T. SHIRASAWA 4 ;
1 Grad. Sch. of Agr., 2 Grad. Sch. of Sci., Kyoto Univ., Kyoto, Japan; 3 Res. Team for Mol.
Biomarkers, Tokyo Metropolitan Inst. of Gerontology, Tokyo, Japan; 4 Dept. of Ageing Control
Med., Juntendo Univ. Grad. Sch. of Med., Tokyo, Japan
Abstract: Aggregation of the 42-residue amyloid β peptide (Aβ42) plays a critical role in the
pathogenesis of Alzheimer‟s disease (AD). Formation of the intermolecular β-sheet is a key