The amyloid fibrils of α-synuclein (α-syn) are crucial in the pathology of Parkinson's disease (PD), with the intrinsically disordered region (IDR) of its C-terminal playing a key role in interacting with receptors like LAG3 and RAGE, facilitating pathological neuronal spread and inflammation. In this study, we identified Givinostat (GS) as an effective inhibitor that disrupts the interaction of α-syn fibrils with receptors such as LAG3 and RAGE through high-throughput screening. By exploring the structure-activity relationship and optimizing GS, we developed several lead compounds, including GSD-16-24. Utilizing solution-state and solid-state NMR, along with cryo-EM techniques, we demonstrated that GSD-16-24 binds directly to the C-terminal IDR of α-syn monomer and fibril, preventing the fibril from binding to the receptors. Furthermore, GSD-16-24 significantly inhibits the association of α-syn fibrils with membrane receptors, thereby reducing neuronal propagation and pro-inflammatory effects of α-syn fibrils. Our findings introduce a novel approach to mitigate the pathological effects of α-syn fibrils by targeting their IDR with small molecules, offering potential leads for the development of clinical drugs to treat PD.

Microtubules are important components of the eukaryotic cytoskeleton. Their structural organization is regulated by nucleotide binding and many microtubule-associated proteins (MAPs). While cryo-EM and X-ray crystallography have provided detailed views of interactions between MAPs with the microtubule lattice, little is known about how MAPs and their intrinsically disordered regions interact with the dynamic microtubule surface. NMR carries the potential to directly probe such interactions but so far has been precluded by the low tubulin yield. We present a protocol to produce [¹³C, ¹⁵N]-labeled, functional microtubules (MTs) from human cells for solid-state NMR studies. This approach allowed us to demonstrate that MAPs can differently modulate the fast time-scale dynamics of C-terminal tubulin tails, suggesting distinct interaction modes. Our results pave the way for in-depth NMR studies of protein dynamics involved in MT assembly and their interactions with other cellular components.

We report a novel proton-detected MAS solid-state NMR strategy based on ¹⁵N–¹⁵N proton assisted recoupling to detect the inter-nucleotide NH⋯N hydrogen bonds within the Watson–Crick base pairs of micro-crystallized dimeric RNA and to confirm the kissing-loop structure. This would contribute to advances in the structural determination of RNA using solid-state NMR.