Manufacturer,provider and supplier of
Recombinant Staphylococcal / Streptococci Protein A ( rProtein A / rSPA)

Description A DNA sequence encoding the Streptococci Protein A (Ala 2-Cys 293) was fused with the polyhistidine tag at the N-terminus.

Molecular mass 299 amino acids and predicts a molecular mass of 33.8 KDa as estimated in SDS-PAGE.

Source E.Coli

Predicted N terminal Met 1

Purity > 97 % SDS-PAGE.

Endotoxin < 1.0 EU per mg

Buffer 100mM NaHCO3, 1mM DTT,1mM EDTA, pH7.5

Can be stored temporarily at 4ºC,usually at -70ºC,avoid repeated freeze-thaw cycles.

A A Sequence
MHHHHHHAQHDEAQQNAFYQVLNMPNLNADQRNGFIQSLKDDPSQSANVLGEAQKLNDS
QAPKADAQQVNFNKDQQSAFYEILNMPNLNEAQRNGFIQSLKDDPSQSTNVLGEAKKLNE
SSAPKADNNKEQQNAFYEILNMPNLNEEQRNGFIQSLKDDPSQSANLLSEAKKLNESQAP
KASNKFNKEQQNAFYEILHLPNLNEEQRNGFIQSLKDDPSQSANLLAEAKKLVDAQAPKAD
NKFNKEQQNAFYELLPNLTEEQRNGFIQSLKDDPSVSKEILAEAKKLNDAQAPKC

Protein Description
Protein A is a 40-60 kDa surface protein originally found in the cell wall of the bacteria Staphylococcus aureus (SPA).SPA binds proteins from many of mammalian species, most notably IgGs, and helps inhibit phagocytic engulfment and acts as an immunological disguise via this type of interaction, thus the bacteria will disrupts opsonization and phagocytosis. SPA is known to bind with Fc region of immunoglobulins preferentially through interaction with the VH3 variable region of the heavy chain. SPA has been shown to bind with high affinity to human IgG1 and IgG2 as well as mouse IgG2a and IgG2b, whereas bind with moderate affinity to human IgM, IgA and IgE as well as mouse IgG3 and IgG1. SPA is often produced in E. coli and is practically coupled to other molecules such as enzymes, biotin, radioactive iodine for use in immunology and other biological research. SPA is also immobilized onto a solid support such as agarose beads for total IgG purifying or interest protein or protein complex identifying in immunoprecipitation studies.

Reference
1. Romagnani, S. et al., 1981, J. Immunol. 127: 1307-1313.
2. Hartleib, J. et al., 2000, Blood. 96: 2149-2156.
3. Kristiansen, S.V. et al., 1994, J. Immunol. 153: 2974-2982.