Protein crosslinking is a useful technique to confirm protein-protein interactions, to generate protein molecules with bi-functionality, or to fix proteins at a desired location. One useful approach is to use heterobifunctional crosslinking reagents. Perhaps the best known such reagent is SMCC. SMCC reacts with primary amines on one end (via NHS-ester) and thiols on the other (via maleimide). Most proteins contain many primary amines but very few (if any) available thiols. One common crosslinking protocol would be to first react SMCC with a protein, and then remove unreacted SMCC. The SMCC activated protein is then exposed to a protein that has available thiols (sulfhydryls), allowing the formation of a covalent bond between the proteins.
Let Protein Mods add thiols to your protein for crosslinking needs. We also provide additional conjugation services. Please inquire for details.