Protein G / Agarose

Protein G / Agarose
Protein G is an immunoglobulin-binding protein expressed in group C and G Streptococcal bacteria. It is a 65-kDa (G148 protein G) and a 58 kDa (C40 protein G) cell surface protein that has found application in purifying antibodies through its binding to the Fc region [1]. Protein G binds to most mammalian IgGs through the Fc region, but some binding also occurs through the Fab region. Native protein G also binds albumin, however, because serum albumin is a major contaminant of antibody sources, the albumin binding site has been removed from recombinant forms of Protein G [2]. Protein G / Agarose from InvivoGen uses the recombinant form of protein G lacking the albumin-binding region.
Binding capacity of Protein G:
- 20 mg of human IgG per ml of gel
- 15 mg of rabbit IgG per ml of gel
- 6 mg of mouse IgG per ml of gel