ABSTRACT
This chapter explains the electromagnetic nature of protein-protein interactions. To understand protein–protein interactions, it is crucial to first have an understanding of protein structure. Obtaining information about the different levels of protein structure is an important problem in both the experimental and the theoretical sciences. In practice, a protein structure is measured (resolved) by either x-ray crystallography, nuclear magnetic resonance, or electron microscopy, but all of these have characteristic drawbacks and challenges. Specificity of biomolecular interactions often imposes restrictions on the variability of the protein's structure, at least in the regions of interest. In addition, the internal motion of a protein over time can often be approximately simulated, using force field–based techniques. The interactions occurring between proteins, or between proteins and other biomolecules, such as DNA, RNA, or small ligands, all arise in one way or another from electromagnetism, as weak and strong interactions, as well as gravity, play virtually no role in the length scales involved.
