CHARACTERIZATION OF β-AMYLOID PEPTIDE AGGREGATION AND ACCELERATION WITH PEPTIDE-BASED MEDIATORS
Nadia J. Edwin, Advisor Paul S. Russo (Louisiana State University)
Protein aggregation occurs under many circumstances, from the dynamic assembly of tubulin to form microtubules, the aggregation of actin into filaments, as well as plaque formation by amyloid precipitation. In Alzheimer’s disease, the improper folding of the β-amyloid peptide has been linked to the cellular malfunction. One important requirement in studying the mechanism of amyloid aggregation is the ability to monitor the growth kinetics over a wide range in size scales (10 nm to microns) with time that spans microseconds to seconds. Understanding the mechanisms of the aggregation may then lead to improved design of drugs to help control or suppress the aggregation process.
In this work, the physical characterization of the β-amyloid peptide and its interaction with αα-disubstituted amino acid peptide-based mediators was investigated from the early, rapidly evolving stage to the later, slowly diffusing peptide stage by the application of fluorescence photobleaching recovery (FPR). The studies showed that the αα-amino acid mediators greatly altered the aggregation kinetics of the β-amyloid peptide and yielded aggregates with nonfibrillar morphology. The results suggest that the αα- amino acid mediators are disrupting the amyloid fibril formation by an alternate assembly pathway.
Nadia J. Edwin
Mentor: Vivek M. Prabhu
Polymers Division, Electronic Materials Group
National Institute of Standards and Technology
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Gaithersburg, MD 20899-8540
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Sigma Xi Member: No