Binding mechanism of single-walled carbon nanotubes (SWCNTs) to serum albumin: spectroscopy and molecular modelling exploration

Considering the large-scale production of diversified nanomaterials, it is of paramount importance to unravel the structural details of interactions between nanoparticles and biological systems at the molecular level, with the aim to reveal the potential adverse biological impacts. Herein, with single-walled carbon nanotubes (SWCNTs) acting as model nanomaterials and bovine serum albumin (BSA) acting as a model protein, a combination of spectroscopy experiments and molecular modelling was applied to help us unravel some important issues on the mechanism of protein interactions with SWCNTs. As a result, SWCNTs were first proved to bind at subdomain IB of BSA based on fluorescence experiments and molecular dynamics modelling. In addition, hydrophobic interactions were recognised as the driving force governing the binding behaviour between the SWCNTs and BSA. As a consequence, SWCNT binding led to a conformational change both at the secondary and tertiary structure levels. Insight into the binding details between BSA and SWCNT can help understand the recognition mechanism between SWCNTs and proteins, thus be helpful to predict the potential adverse effects of SWCNTs.