Ig modules as discrete structural units to exploit functional and structural aspects of Ig-like receptors

Summary

Ig-like receptors derive their name from the presence of immunoglobulin-like domains in their extracellular moieties. The Ig module is the most widespread protein fold in nature, with more than a thousand members found in the most diverse and evolutionarily distant protein families. The simple architecture of the Ig fold makes it ideal for structural and functional studies as isolated module. In the field of Fc receptors, we describe here two examples of single Ig modules usage. The first application helps the understanding of FcεRI binding and folding by studying the membrane-proximal Ig module (α2) of the receptor α-chain. In the second strategy, the heavy chain C-terminal Ig module of human immunoglobulins (eg, CH3 for IgG and CH4 for IgE) allows the design of dimeric molecules with good potentials for clinical and biotechnological applications.