Protein Labeling & Modification

Proteins are composed of polypeptide chains and their biological functions are determined in part by the correct folding, size, and the number of reactive functional groups present throughout the polypeptide chain. The ability to provide site-specific protein modifications provides researchers with the ability to investigate a wide range of properties and their overall biological function. Protein labeling and modifications technologies include adding fluorophores, biotin, and other small molecules to examine protein-protein interactions, protein folding, to investigate the overall protein structure, and their biological function. 

Fluorescent Protein Labeling

The discovery and wide-spread incorporation of green fluorescent protein (GFP) is a powerful example of this technology. GFP and its counterpart molecules have had an enormous impact on numerous fields of study and our understanding of biological processes. For example, the incorporation of fluorescent tags onto antibodies allows for the detection and quantification of highly specific protein complexes in tissues or the directional immobilization of antibody-protein complexes for ELISA and western blot applications. However, a significant disadvantage of using GFP is that the protein function may be disrupted by the incorporation of additional protein tags of this size. To circumvent this challenge, researchers may use smaller fluorescent tags compared to a GFP, biotin, or incorporate non-natural amino acids that contain biorthogonal functionality.