Protein A, 434 a.a

Recombinant Staphylococcal Protein A is a non-glycosylated polypeptide chain containing 434 amino acids (37-469 a.a.) and has a molecular mass of approximately 48.1 kDa . The recombinant version is produced by expressing a modified protein A gene in Escherichia coli (E. coli) . This process ensures high purity and specificity, with the recombinant protein A being purified using proprietary chromatographic techniques .

The amino acid sequence of Staphylococcal Protein A 434 a.a includes multiple repeats of the IgG-binding domains, which are responsible for its high affinity and specificity for the Fc region of immunoglobulins .

Recombinant Protein A is widely used in both research and bioprocessing due to its ability to bind with high specificity to IgG. This makes it an invaluable tool for various applications, including:

• Affinity Chromatography: Used to purify antibodies from complex mixtures.
• Immunoprecipitation: Helps in isolating specific proteins from cell lysates.
• Diagnostic Assays: Utilized in various immunoassays to detect the presence of antibodies.

The production of recombinant Staphylococcal Protein A involves expressing the protein in E. coli. The purification process is stringent, ensuring that the final product is free from bacterial contaminants such as endotoxins and hemolysin . The protein solution is typically formulated with 20mM Tris-HCl, pH 8, and 10% glycerol to maintain stability .

For short-term storage (2-4 weeks), the protein can be kept at 4°C. For longer periods, it is recommended to store the protein at -20°C with the addition of a carrier protein (0.1% HSA or BSA) to prevent degradation . It is crucial to avoid multiple freeze-thaw cycles to maintain the protein’s integrity .