Title
Nano Zinc Oxide Inhibits Fibrillar Growth and Suppresses Cellular Toxicity of Lysozyme Amyloid
Author
Deependra Kumar Ban, Subhankar Paul
Year
2016
Journal
Applied Materials & Interfaces
Abstract
Deposition of amyloid fibers has been a common pathological event in number of neurodegenerations such as Alzheimer’sdisease, Parkinson disease, Prion disease. Although, various therapeutic interventions have been reported; nanoparticles have recently been considered as possible inhibitor of amyloid fibrillation. Here, we reported the effect of three different forms of zinc oxide nanoparticles (ZnONP): uncapped (ZnONPuncap), starch capped (ZnONPST) and self-assembled (ZnONPassmb) (average size of 10, 30 and 163 nm, respectively) having a core size of 10-15 nm, in the amyloid growth of hen egg white lysozyme (HEWL). We monitored the amyloid growth by electronmicroscopy as well as Thioflavin-T (ThT) measurement. We observed that ZnONP demonstrated a dose-dependent inhibition of fibrillar amyloid growth of HEWL with highest effect exhibited by ZnONPST. Such inhibition was also associated with decrease of cross β-sheet amount, surface hydrophobicity as well as increase of stability of proteins. Further, we observed that ZnONPST prolonged the nucleation phase and shortened the elongation phase of HEWL amyloid growth. Although pure amyloid caused profound cellular toxicity in both mouse carcinoma N2a and normal cells such as human keratinocytes HaCaT cells, amyloid formed in the presence of ZnONP showed much reduced cellular toxicity. We also observed that inhibition of amyloid growth was effective when ZnONP were administered during the lag phase. When our amyloid inhibition results were compared with a well-known inhibitor curcumin, we observed that ZnONPST demonstrated a better inhibitory effect than curcumin. Overall, we reported here the inhibitory activity of three different forms of ZnONP to amyloid fibrillation of HEWL and amyloid-mediated cytotoxicity to different extent while starch capped ZnONP showed the highest fibrillation inhibitory effect.
Full Article
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Nanostructures, Materials, Aggregation, Biochemistry