85-2067-46　Protein G, Recombinant 1mg　209158

特徴

• Protein G is a bacterial cell wall protein isolated from group G Streptococci. Native Protein G contains two IgG-binding domains and sites for albumin and cell surface binding. The albumin and cell surface binding domains have been eliminated from purified Recombinant Protein G to reduce nonspecific binding and, therefore, can be used to separate IgG from crude samples. Optimal binding occurs at pH 5, although binding is also good at pH 7.0-7.2. Protein G has greater affinity than Protein A for most mammalian IgGs, it may be used for the purification of mammalian IgGs that do not bind well to Protein A. Protein G does not bind to human IgM, IgD and IgA.
• Native protein is ~65kD. It contains two albumin binding domains at the N-terminus and 3 IgG binding domains (~55aa each) at the C-terminus. Recombinant protein G does not contain albumin binding domains. Differences in binding characteristics between Protein A and Protein G may be explained by the differing compositions in the IgG-binding sites of each protein, and sequence differences between Protein A and Protein G. Variations in isolation and purifications methods for Protein G may affect IgG binding, partially because there are differing numbers of IgG-binding sites on various sources of Protein G.
• Source:Recombinant protein corresponding to Protein G from Staphylococcus Group G, expressed in E. coli.
• Molecular Weight:~23kD, migrates to ~32kD protein
• Binding Capacity:1mg binds 10-15mg of human IgG. Binding of other species may be different.
• Endotoxin:<0.5EU/mg protein
• Storage and Stability:Lyophilized powder may be stored at -20°C. Reconstitute with sterile ddH2O or PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.