Native protein A (Protein A) is a cell wall surface protein found in Staphylococcus aureus, and native protein G (Protein G) is a cell surface protein isolated from G-type or C-type Streptococcus. The two have similar functions and can bind to most mammalian IgG mainly by interacting with the Fc region of immunoglobulin (Ig). However, the two have different binding specificities (see Appendix 1 for details, a summary of the binding ability of protein A, G and L to Ig of different species). For example, protein G has a high affinity for human being IgG3, rat IgG2a, and sheep IgG1, but protein A has a weak binding ability to these Igs. Protein A and protein G are often covalently coupled to solid carriers such as agarose beads or acrylic resin beads, and are directly used for immunoprecipitation (IP) or co-immunoprecipitation (Co-IP) to conduct protein function-related studies, or directly loaded on a chromatography column to purify monoclonal or polyclonal antibodies. This product is produced in E. coli. The recombinant protein A/G consists of 7 IgG binding domains EDABC-C1C3, corresponding to 5 IgG binding regions of protein A and 2 IgG domains of protein G. The binding capacity of recombinant protein A/G is broader than that of protein A or protein G alone. The cell wall binding region, cell membrane binding region and albumin binding region of recombinant protein A/G have been removed, reducing cross-reaction and non-specific binding, ensuring the maximum specific binding of IgG. Specifications Source E.coli Molecular Weight Approximately 47.8 kDa with a Cys on N-terminus, a single non-glycosylated polypeptide chain containing 430 amino acids. Amino acid sequence CNAAQHDEAQ QNAFYQVLNM PNLNADQRNG FIQSLKDDPS QSANVLGEAQ KLNDSQAPKA DAQQNNFNKD QQSAFYEILN MPNLNEAQRN GFIQSLKDDP SQSTNVLGEA KKLNESQAPK ADNNFNKEQQ NAFYEILNMP NLNEEQRNGF IQSLKDDPSQ SANLLSEAKK LNESQAPKAD NKFNKEQQNA FYEILHLPNL NEEQRNGFIQ SLKDDPSQSA NLLAEAKKLN DAQAPKADNK FNKEQQNAFY EILHLPNLTE EQRNGFIQSL KDDPSVSKEI LAEAKKLNDA QAPKEEDSLE GSGSGTYKLI LNGKTLKGET TTEAVDAATA EKVFKQYAND NGVDGEWTYD DATKTFTVTE KPEVIDASEL TPAVTTYKLV INGKTLKGET TTKAVDAETA EKAFKQYAND NGVDGVWTYD DATKTFTVTE The concentration of 1 unit DO at 280 nm 1.737 mg/ml Appearance Sterile filtered white lyophilized powder Label None Purity > 96% by SDS-PAGE and HPLC analyses Endotoxin levels < 0.1 EU/μg of protein by the LAL method formula No additives, freeze-dried Reconstitution Distilled water or saline solution Storage Transport with ice packs. Store at -20℃, valid for one year. It is recommended to store in small portions for first use to avoid repeated freezing and thawing. Note 1. 1. For your safety and health, please wear a lab coat and disposable gloves when operating. 2. This product is for scientific research purposes only.. Appendix 1. Summary of the binding capacity of proteins A, G and L to Ig from different species Species Protein A Protein G Protein L Species Protein A Protein G Protein L Human IgG +++ +++ +++ Sheep IgG + ++ - IgG1 ++++ ++++ ++++ IgG1 + ++ - IgG2 ++++ ++++ ++++ IgG2 +++ +++ - IgG3 - +++ +++ Dog ++ + NT IgG4 ++++ ++++ ++++ Pig +++ ++ +++ IgA + - +++ Rat IgG + ++ +++ IgA1 + - +++ IgG1 - + +++ IgA2 + - +++ IgG2a - ++++ +++ IgD - - +++ IgG2b - ++ +++ IgE ++ - +++ IgG2c ++ ++ +++ IgM + - +++ IgG3 + ++ NT Rabbit IgG +++ +++ + Mouse IgG ++ ++ +++ Cow IgG + +++ - IgG1 + ++++ +++ IgG1 + +++ - IgG2a ++++ ++++ +++ IgG2 +++ +++ - IgG2b +++ +++ +++ Cat IgG +++ + NT IgG3 ++ +++ +++ Horse IgG ++ ++++ NT IgM - - +++ Goat IgG + ++ - Chicken IgY - - - IgG1 + +++ - Monkey IgG ++++ ++++ NT IgG2 +++ +++ - Hamster + ++ +++ Guinea-pig IgG1 ++ + NT Koala - + NT IgG2 ++ + NT Llama - + NT Strong binding (＋＋), medium interaction (＋), weak or no interaction (－), not tested (NT) .
