Studies on Effect of Proline Capped Gold Nanoparticles on Hen Egg White Lysozyme (HEWL) and Cytochrome C (Cyt C) Amyloidogenesis

Abstract

A number of dreadful neurodegenerative diseases like Alzheimer’s, Parkinson’s and Amyotrophic lateral sclerosis (ALS) are caused by the culmination of their associated proteins native structure to self-assembled extremely stable fibrils called amyloids. Amyloidogenesis, the process of amyloid formation, is a mechanism still shrouded in mystery. In our present study, we have used the imino acid Proline which is a well known chemical chaperone and is known to interact with Gold colloids, to synthesize Gold Nanoparticles (AuNPs) capped with the same and explore its anti-amyloidogenic ability. The synthesized Proline Capped Gold Nanoparticles (Pro-AuNPs) were vigorously characterized by various techniques like Ultraviolet-Visible (UV) Spectroscopy, Fourier Transform Infra-Red (FTIR) spectroscopy, Dynamic Light Scattering (DLS), Zeta potential measurement and Transmission Electron Microscopy. Our exploration on the anti-amyloidogenic activity of Proline and Pro-AuNPs on two completely unrelated model proteins, namely Hen Egg White Lysozyme (HEWL) and Cytochrome C (Cyt C), unveiled interesting facets to the process. We conclude that irrespective of the evolutionary relationship of all proteins, the process of amyloidogenesis follows a common route driven by a common force. Therefore, it is a great possibility that there might as well be a common inhibitor for all amyloidosis. We also conclude that the effect of inhibition is independent of the charge of the inhibitor and isoelectric point of the protein, rather the chemical structure of the inhibitor is important in the process, which in this case, is the Pyrollidone ring of Proline. We have also seen that conjugation of Proline with AuNPs increases its anti-amyloidogenic tendency by increasing local concentration.