Changes in Bovine Serum Albumin (BSA) conformation in the presence of silver nanoparticles (AgNPs)

Blood proteins are the first biological components to interact with a material when it is introduced into an organism. Any alteration in the three-dimensional structure of these proteins can compromise their function. Moreover, the biological response to a material is significantly influenced by protein adsorption—not only in terms of the amount but also the type and structural conformation of the proteins involved [1].

Silver nanoparticles (AgNPs), on the other hand, are biomaterials with promising properties for medical applications. Motivated by this, we set out to study the behavior of a system composed of bovine serum albumin (BSA) and AgNPs.

In this work, we employed density and speed-of-sound measurements to calculate specific volume and adiabatic compressibility. In parallel, we used dynamic light scattering (DLS) and fluorescence spectroscopy to gain insights into protein conformation. The combined data suggest the presence of a balance between metal-enhanced fluorescence (MEF) and surface energy transfer (SET) effects—both dependent on the distance between tryptophan (Trp) residues and the AgNPs [2].

Volumetric and compressibility analyses also revealed changes in the protein’s tertiary structure [3]. DLS results exhibited two distinct peaks: the first corresponding to BSA monomers in their native state and the second to larger aggregates, clearly indicating protein aggregation [4].