Recombinant Protein G

Protein G is relatively small protein commonly used to bind antibodies. Protein G was first identified in the cell wall of the bacterium Group G Streptococcus and contains three IgG binding domains. The primary function of Protein G is to specifically bind to the Fc (fragment crystallizable) region of antibodies, which is the constant region of the antibody molecule and is conserved among mammalian species.

Accordingly, protein G has a high affinity for a wide range of mammalian antibodies, including human, mouse, rat, and rabbit. This makes it a versatile tool in research applications, such as protein purification, antibody detection, and immunoprecipitation. Protein G can be immobilized on various surfaces, such as beads or columns, to capture and isolate specific antibodies from complex biological samples such as serum or ascites fluid.

An unusual feature of Protein G is its ability to bind a variety of classes of antibodies, including IgG, IgA, and IgM. Protein G also exhibits different binding profiles depending on the species and subclass of the antibody, which allows for fine-tuning of antibody purification and detection protocols in different experimental settings.

Our recombinant protein A includes a 6x histidine tag for ease of purification and has been engineered to not include the albumin binding site. Calculated MW is 21 kDa.