Intrinsically disordered proteins (IDPs) lack a stable three-dimensional structure under physiological conditions and play a crucial role in neurodegenerative diseases. α-Synuclein (α-syn), an intrinsically disordered protein is highly prone to aggregation and thereby acts as a central therapeutic target in Parkinson’s disease and other synucleinopathies. Considering their role as a therapeutic target, robust list of compounds is being explored to suppress the activity of α-syn such as polyols, osmolytes, and many natural compounds. A naturally occurring brain osmolyte, myo-inositol (MI), has yet been unexplored. In this study, we have expressed, purified and biophysically characterized the effect of MI on α-syn aggregation. Optimal expression of α-synuclein was achieved at 1 mM IPTG induction at 37°C. For biophysical characterization, multiple techniques were employed. UV-visible spectroscopy showed a characteristic absorbance peak at 275 nm. Fluorescence spectroscopy revealed an emission maximum near 305 nm, attributable to tyrosine residues, consistent with α-syn’s composition of four tyrosines. Far-UV circular dichroism (CD) spectroscopy demonstrated a strong negative band at 200 nm, confirming its predominantly random coil nature and validating its classification as an IDP. The impact of MI on α-syn aggregation was further evaluated using time-resolved Thioflavin T (ThT) fluorescence and Rayleigh light scattering (RLS) assays. Both assays indicated significant α-syn aggregation after incubation at 37°C and 220 rpm for 96 h. Notably, MI exhibited a pronounced anti-aggregation effect, reducing the extent of fibril formation. This study provides the first evidence of MI’s ability to modulate α-syn aggregation. Although MI has previously been explored as a therapeutic agent in psychiatric and mood disorders, our findings highlight its potential utility in preventing or slowing α-syn aggregation. These results position MI as a promising candidate for therapeutic intervention in α-synucleinopathies and related neurodegenerative diseases.
ASHIQ MAHAMMAD (Sun,) studied this question.