Molecular interaction of proteins and peptides with nanoparticles.

The interaction of proteins in living cells is one of the key processes in the maintenance of their homeostasis. Introduction of additional agents into the chain of these interactions may influence homeostatic processes. Recent advances in nanotechnologies have led to a wide use of nanoparticles (NPs) in industrial and biomedical applications. NPs are small enough to enter almost all compartments of the body, including cells and organelles, and to complicate the pattern of protein interactions. In some cases, interaction of nanoscale objects with proteins leads to hazardous consequences, such as abnormal conformational changes leading to exposure of cryptic peptide epitopes or the appearance of abnormal functions caused by structural modifications. In addition, the high local protein concentration resulting from protein adsorption on NPs may provoke avidity effects arising from close spatial repetition of the same protein. Finally, the interaction of NPs with proteins is known to induce cooperative effects, such as promotion or inhibition of protein fibrillation or self-assembling of NPs on macromolecules serving as a template. It is obvious that better understanding of the molecular mechanisms of nano-bio interactions is crucial for further advances in all nanotechnological applications. This review summarizes recent progress in understanding the molecular mechanisms of the interactions between proteins or peptides and NPs in order to predict the structural, functional, and/or nanotoxic consequences of these interactions.