Targeting Lysozyme-Linked Amyloidosis through Piperine-Functionalized Gold Nanoparticles

Excess accumulation of misfolded and mutated human lysozyme (HuL) is the pathological hallmark of non-neuropathic systemic amyloidosis. These deposits are rich in cross β-sheet conformers and often exist as polymorphic fibrillar structures, which makes it a tricky and challenging task to design therapeutic interventions toward HuL-linked amyloidopathy. Here we aimed to design an effective antiamyloid metal nanoparticle formulation to target the exposed hydrophobic and aggregation-prone stretches in HuL. Initially, we synthesized and characterized piperine-coated gold nanoparticles (AuNPs^Pip). ThT-probed aggregation studies of HuL in the presence and absence of AuNPs^Pip revealed an inhibition of lysozyme aggregation. This inhibition effect was confirmed through dynamic light scattering (DLS) and fluorescence microscopy analyses. We further investigated whether AuNPs^Pip could bind to preformed fibrils and prevent the secondary nucleation process, which is a crucial step in amyloidogenesis. Our results showed that AuNPs^Pip not only prevented seed-induced aggregation but also disassembled preformed amyloid aggregates, which was not observed with AuNPs or piperine. Experimental and computational studies suggest that the retention of the lysozyme native structure and the ability of AuNPs^Pip to interact with the aggregation-prone residues are key factors in the inhibition mechanism. The findings of this work may aid in developing nanoparticle-based formulations to prevent pathologies linked to lysozyme aggregation.