Wang S.S.-S.Becerra-Arteaga A.Good T.A.2019-05-092019-05-09200200063592https://scholars.lib.ntu.edu.tw/handle/123456789/406778£]-Amyloid peptide (A£]) is the primary protein component of senile plaques in Alzheimer's disease and is believed to be responsible for the neurodegeneration associated with the disease. A£] is toxic only when aggregated, however, the size and structure of the aggregated species associated with toxicity is unknown. In the present study, we developed a diffusion-based method to simultaneously separate and detect the biological activity of toxic A£] oligomers and used the method to examine the relationship between size of aggregated protein and toxicity to SH-SY5Y cells. From these measurements, the effective diffusivity and hydrodynamic radius of the toxic oligomeric species of A£] could be determined. A sensitivity analysis was performed to examine the effects of model assumptions used in data analysis on the effective diffusivity calculated. The method provides a new estimate of the size of small toxic A£] species associated with fibril formation. This work contributes to our understanding of the relationship between A£] structure and toxicity and with further refinements may aid in our ability to design agents which alter the A£] aggregation/dissociation processes associated with neurotoxicity. ? 2002 Wiley Periodicals, Inc.Alzheimer's diseaseA£]DiffusionDiffusion coefficientMolecular weightNeurotoxicityjournal article10.1002/bit.103472-s2.0-0037026929https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037026929&doi=10.1002%2fbit.10347&partnerID=40&md5=2f6e06b77b1365ac6d36bba44e3732be