Interactions of a small molecule configuration mimetic the interactions
found in α-synuclein aggregation
Abstract
Parkinson’s disease (PD) is an increasingly prevalent and currently
incurable neurodegenerative disorder. The aggregation of the amyloid
disordered protein α-synuclein (Syn) has been implicated in the
development of PD. Syn aggregation has been widely investigated but
information concerning the conformational alterations in the diverse
protein aggregated species at the molecular level is still scarce. To
address this issue, it was here developed a comparative study involving
the known parent N α-acetyl-L-tyrosinamide (NAYA)
compound and the Syn protein by using spectroscopic techniques. At least
two different configurations of the NAYA compound were found to exist in
solution. One configuration, known as the NAYA closed shape
configuration, involves an amide intramolecular hydrogen-bonded
interaction and was found to be a model interaction for the hydrophilic
core of β-sheets, which are the most common conformational alteration
found in Syn aggregated species. Since the spectroscopic techniques used
herein also differentiate between tyrosyl and peptide bond groups and
both NAYA and Syn possess such groups it was possible to assign these
groups interactions in the β-sheets formed. This study retrieves the
importance of using model compounds with spectroscopic characteristics
similar to those found in proteins to access the complex interactions
network existing in the amyloid aggregated species.