Silver nanoparticle modulates the aggregation of beta-lactoglobulin and induces to form rod-like aggregates

Silver nanoparticles (SNPs) have been increasingly used in medicines and biomaterials as a drug carriers and diagnostic or therapeutic material due to their smaller size, large surface area and cell penetration ability. Here we report the preparation of SNPs of diameter 10 +/- 3 nm by using silver nitrate and sodium borohydride and the interaction of synthesized SNPs with our model protein beta-lactoglobulin ([beta-lg) in 10 mM phosphate buffer at pH 7.5 after thermal exposure at 75 degrees C. Heat exposed beta-lg forms amyloidal fibrillar aggregates whereas this protein aggregates adopt rod-like shape instead of fibrillar structure in presence of SNP under the same conditions. Size of the synthesized SNPs is confirmed by UV-Visible spectroscopy, SEM and TEM. Interactions and subsequent formation of molecular assembly of heat stressed beta-lg with SNP were investigated using Th-T assay and ANS binding assay, DIS, RLS, CD, FT-IR, SEM, TEM. Docking study parallely also support the experimental findings. (C) 2018 Elsevier B.V. All rights reserved.