Protein A/G
Description
The recombinant Protein A/G consists of 5 IgG-binding regions of protein A and 2 of protein G, which corresponds to the Protein A and G domains that are included in the recombinant sequence. Cell wall binding region, cell membrane binding region and albumin binding region have been removed from the recombinant Protein A/G to ensure the maximum specific IgG binding. The Protein A portion is from Staphylococcus aureus segments E, D, A, B and C. The Protein G portion is from Streptococcus segments C1 and C3. The fusion protein has a predicted molecular mass of 47.7kDa and containing 429 amino acids.
Product Specs
Recombinant Protein A/G is engineered to optimize IgG binding. It comprises five IgG-binding regions derived from protein A and two from protein G, representing the core binding domains of these proteins. This recombinant version excludes the cell wall binding region, cell membrane binding region, and albumin binding region, ensuring highly specific IgG binding. Specifically, the Protein A portion originates from Staphylococcus aureus segments E, D, A, B, and C, while the Protein G portion comes from Streptococcus segments C1 and C3. With a predicted molecular mass of 47.7kDa, this 429-amino acid fusion protein is a powerful tool for IgG purification and detection.
To maintain stability, it is recommended to aliquot the reconstituted Protein A/G and store it at -20°C. Repeated freezing and thawing should be avoided.
Product Science Overview
Protein A is a bacterial protein originally found in the cell wall of Staphylococcus aureus. It consists of five IgG-binding domains (E, D, A, B, and C) and has a high affinity for the Fc region of immunoglobulins, particularly IgG. This binding property makes Protein A useful for purifying and detecting antibodies. Recombinant Protein A is produced in E. coli and retains the same binding characteristics as the native protein .
Protein G is derived from Streptococcus species and contains three IgG-binding domains (C1, C2, and C3). Unlike Protein A, Protein G can bind to a wider range of IgG subclasses, including those from species that do not bind well to Protein A, such as mouse IgG1 and human IgG3 . Recombinant Protein G is engineered to remove albumin and Fab binding domains, enhancing its specificity for the Fc region of immunoglobulins .
The recombinant fusion of Protein A and Protein G results in Protein A/G, which includes the IgG-binding domains from both proteins. This fusion protein is designed to capture immunoglobulins from a wider range of species and antibody isotypes than either Protein A or Protein G alone . The combination of these domains allows Protein A/G to bind strongly to rabbit, mouse, human, and other mammalian IgG subclasses .
Protein A/G Recombinant is widely used in various immunological techniques, including:
- Immunoprecipitation (IP) and Co-Immunoprecipitation (Co-IP): Protein A/G is used to isolate and purify specific antigens or proteins from complex mixtures by binding to antibodies that are specific to the target protein .
- Antibody Purification: It is used to purify antibodies from biological fluids such as serum, ascites, or cell culture supernatants .
- Western Blotting: Protein A/G can be used to detect antibodies in Western blot assays, providing a versatile tool for protein analysis .
The main advantages of using Protein A/G Recombinant include:
- Broad Binding Range: It can bind to a wide range of IgG subclasses from different species, making it highly versatile .
- High Affinity: The fusion protein retains the high-affinity binding properties of both Protein A and Protein G .
- Reduced Background: The use of recombinant technology ensures high purity and low background in experimental applications .
