A Primer for Junior Trainees: The Structure, Binding, and Therapeutic Applications of Immunoglobulin G

Immunoglobulin G (IgG) is a central component of the immune system, a vital tool in research and diagnostics, and has become a cornerstone of next-generation therapeutics. Despite their diverse applications in biology and human medicine, all IgGs function by specifically recognizing their target molecules. Its unique structure facilitates a diversity of protein sequence combinations to recognize a diversity of antigen targets. Because of this flexibility, antibodies have been usurped to create novel therapeutics that can promote or prevent protein-protein interactions. This junior trainee review introduces the structure and general binding mechanism of IgG and explores how its form underlies its biological and therapeutic functions. The unique structural and biophysical properties of IgG drive its versatility. Examples of current and emerging IgG therapeutics illustrate how fundamental mechanisms in IgG-protein interactions permit this molecule to be a novel strategy to combat a wide variety of diseases.