Protein A
Description
Recombinant Staphylococcal Protein A is purified by proprietary chromatographic techniques.
Product Specs
Product Science Overview
Protein A consists of five homologous immunoglobulin-binding domains, each folding into a three-helix bundle. These domains can bind to the Fc region of immunoglobulins, particularly IgG, from various mammalian species . This binding disrupts opsonization and phagocytosis, allowing Staphylococcus aureus to evade the host’s immune response .
Recombinant Protein A is produced by expressing a modified protein A gene in Escherichia coli (E. coli). This recombinant form retains the essential properties of native Protein A, including its ability to bind immunoglobulins . The recombinant version is often used to increase specificity for IgG and is widely utilized in research and bioprocessing .
Recombinant Protein A is used in various applications, including:
- Affinity Chromatography: It is used to purify antibodies by binding to the Fc region of IgG.
- Immunoprecipitation: It helps in isolating and concentrating specific proteins from complex mixtures.
- Diagnostic Assays: It is used in assays to detect the presence of antibodies or antigens.
The discovery of Protein A dates back to 1940 when Verwey reported a protein fraction from Staphylococcus aureus that non-specifically precipitated rabbit antisera . In 1958, Jensen confirmed these findings and designated the active component as Antigen A. Later, in 1962, Löfkvist and Sjöquist corrected the classification and confirmed that Antigen A was indeed a surface protein on the bacterial wall of certain strains of S. aureus .
