Effect of Green Synthesis of Gold Nanoparticles (AuNPs) from Hibiscus sabdariffa on the Aggregation of α-Lactalbumin

Abstract

Amyloidosis are a hereditary or acquired disorders, which are associated with misfolding of normally soluble, functional peptides and proteins, and their conversion into contentious aggregation can cause amyloid fibrils. These fibrils reduce function of the proteins and with generation of toxic intermediates in the process of self-assembly cause amyloid diseases such as Alzheimer, Parkinson, etc. Nanoparticles are materials with a dimension of 1–100 nm that influence the process of protein fibrillation since nanoparticles mediated by chemical methods have been show side effects, biological methods have been preferred due to its safety for human therapeutic use. In this study, the effect of gold nanoparticle produced from hibiscus on the amyloid formation of α-lactalbumin was evaluated using light scattering absorption, fluorescence (ThT assay, intrinsic fluorescence assay and ANS binding assay), TEM, CD spectroscopy and SDS-PAGE. α -Lactalbumin has been chose as a good sample for study the amyloid formation due to the formation of molten globule state. The results show that AuNPs inhibit formation of amyloid fibrils in reduced α-lactalbumin. This protective effect resulted are due to increase protein adsorption to the surface of the nanoparticles and therefore prevents their structural changes. Nanoparticle by binding to the monomer prevented them from join together and elongation the core of amyloid fibrils. Finally, the results show that biosynthesized AuNPs mediated by hibiscus can be used as effective therapeutic agent for prevention of formation amyloid and treatment of amyloid disease.