FcDOCKER™ Binding Agent

Engineered Protein for IgG Purification

Specific for glycosolated Fc region

FcDOCKER™ is the third Antibody Tool that has been derived from Streptococcus pyogenes. This protein is a mutated form of the endoglycosidase, EndoS, in which residue 235 is altered from glutamate to glutamine. This simple change completely inactivates the carbohydrate cleavage, but still maintains the strong binding affinity for the core glycan of IgG molecules. FcDOCKER binds to all subclasses of glycosylated IgG, and binds selectively to the Fc domain of these molecules. And because FcDOCKER does not bind the Fab region, this makes it a great tool for selectively purifying Fc fragments from a pool of F(ab) and Fc molecules. Astonishingly, FcDOCKER Binding Agent has broader species-affinity for IgG molecules than both Protein A and Protein G combined! It can recognize glycosolated IgG molecules from a very broad range of animals.

Tag and snag your IgGs

The FcDOCKER has been engineered to include a histidine tag – allowing for use of standard separation technologies to isolate glycosylated IgG. This provides a plethora of bind/elute strategies and reagents with which to work.   Best of all, bound glycosylated IgG molecules are simply dissociated from FcDOCKER with the addition of a competing disaccharide such as sucrose. There is no need to elute with harsh, acidic, glycine buffers commonly required for Protein A and Protein G purification protocols.  And what remains is pure glycosolated IgG – no degradation or denaturation. See an example of purification of IgG from whole serum, but you can purify from other matrices as well, such as milk.