Biophysical Society Thematic Meeting - October 25-30, 2015

Polymers and Self Assembly: From Biology to Nanomaterials Poster Session I

40-POS Board 40 Structural Characterization of the Interactions Between B-amyloid 1-40 Peptide and Alpha- Synuclein Protein Involved in Lewy´s Body Diseases Juliana Santana UFRJ, Duque de Caxias, Brazil Protein misfolding and aggregation are features shared by some proteins involved in neurodegenerative diseases. The beta amyloid (AB) peptide, alpha synuclein protein (α-syn) and Tau are related to Alzheimer's Disease (AD), Parkinson's (PD) and tauopathies. Those diseases are implicated in amyloid fibril formation. The symptoms displayed by those diseases are similar and results in cognitive and motor deficit. It has been proposed that the AB 1-40 and AB 1-42 peptide may be found in the extracellular environment in which it could form fibers or in the intracellular environment maintaining its oligomeric form depending on the point at which the amyloid precursor protein (APP) has been cleaved. The a-syn protein contains 140 amino acids and initially observed to be localized at presynaptic terminals. In the case of dementia associated with Lewys Bodies both the AB peptide and a-syn protein are found co-aggregated. Thus, leading to the hypothesis that there is a synergism between the peptide and the protein to promote the aggregation into fibrillar structures.This work aims to improve the knowledge regarding the molecular interactions involved between the proteins (a-syn) and peptide AB 1-40 in the formation of protein aggregates. For that, it has been applied fluorescence spectroscopy, circular dichroism, Nuclear Magnetic Resonance State liquid and Solid State.The AB 1-40 peptide was purified and the purity analyzed by SDS-PAGE gel. The oligomeric state of association between AB 1-40 and alpha synuclein has been evaluated by means of fluorescence polarization measurements, while the molecular interactions has been followed by Nuclear Magnetic Resonance.

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