Introduction
Engineered by combining specific domains from Protein A and Protein G, recombinant Protein A/G boasts an enhanced IgG binding capacity. This chimeric protein incorporates seven IgG-binding domains: EDABC from Staphylococcus aureus Protein A and C1C3 from Streptococcus Protein G. This design enables broader specificity compared to its parental proteins, making it highly effective for purifying both monoclonal and polyclonal IgG antibodies from various species, including human, mouse, rat, cow, goat, sheep, horse, rabbit, guinea pig, pig, dog, and cat. Notably, it exhibits affinity for human IgG subtypes 1, 2, 3, and 4, mouse IgG subtypes 2a, 2b, and 3, and rat IgG subtypes 2a and 2c.
Description
Recombinant Protein A/G, produced in E. coli, is a non-glycosylated polypeptide chain with a C-terminal cysteine residue. This engineered protein consists of five IgG-binding regions derived from Protein A (E-D-A-B-C) and two from Protein G (C1-C3), totaling 430 amino acids and exhibiting a molecular weight of 47.8 kDa. To maximize specific IgG binding, the recombinant Protein A/G lacks the cell wall binding region, cell membrane binding region, and albumin binding region.
Physical Appearance
White, lyophilized powder, sterilized by filtration.
Formulation
Protein-A/G is lyophilized without the addition of any excipients.
Solubility
For reconstitution, it is advised to dissolve the lyophilized Protein-A/G in sterile 18 MΩ·cm water to a minimum concentration of 0.1 mg/ml. This solution can be further diluted with other aqueous solutions as needed.
Stability
Lyophilized Protein-A/G remains stable at room temperature for up to three weeks. However, for extended storage, it should be stored in a dry environment below -18°C. After reconstitution, Protein-A/G can be stored at 4°C for 2-7 days. For long-term storage, freezing at -18°C is recommended, ideally with the addition of a carrier protein like 0.1% HSA or BSA. Repeated freeze-thaw cycles should be avoided.
Purity
The purity of this product exceeds 96.0%, as determined by High-Performance Liquid Chromatography (HPLC) and Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis.
Amino Acid Sequence
NAAQHDEAQQ NAFYQVLNMP NLNADQRNGF IQSLKDDPSQ SANVLGEAQK LNDSQAPKAD AQQNNFNKDQ QSAFYEILNM PNLNEAQRNG FIQSLKDDPS QSTNVLGEAK KLNESQAPKA DNNFNKEQQN AFYEILNMPN LNEEQRNGFI QSLKDDPSQS ANLLSEAKKL NESQAPKADN KFNKEQQNAF YEILHLPNLN EEQRNGFIQS LKDDPSQSAN LLAEAKKLND AQAPKADNKF NKEQQNAFYE ILHLPNLTEE QRNGFIQSLK DDPSVSKEIL AEAKKLNDAQ APKEEDSLEG SGSGTYKLIL NGKTLKGETT TEAVDAATAE KVFKQYANDN GVDGEWTYDD ATKTFTVTEK PEVIDASELT PAVTTYKLVI NGKTLKGETT TKAVDAETAE KAFKQYANDN GVDGVWTYDD ATKTFTVTEC.