Protein G, Recombinant

Protein G lacking the albumin binding region (avoids undesirable reactions with albumin); Fc binding domain is still present. \n\nEach Protein G molecule can bind 2 molecules of IgG, allowing the formation of a precipitate. \n\nProtein G is a small globular cell surface protein produced by Streptococcus sp. It is composed of two or three nearly identical domains of 55 amino acids each. It binds to Fc fragment of IgG with high affinity. Protein G will bind IgGs from many species including all human and mouse subclasses. It does not recognize IgM, IgA, IgE or serum albumin. Protein G binds IgG from rat,, but substantially more weakly than IgG from other species.\n\nRecombinant Protein G is a highly stable surface receptor from Streptococcus sp. Lancefield Group G, produced in Escherichia coli, which is capable of binding the Fc portion of immunoglobulins, especially IgGs, from a large number of species (Boyle and Reis, 1987).\n\nProtein G may be coupled to a wide variety of reporter molecules including fluorescent dyes, enzyme markers, biotin, colloidal gold and radioactive iodine without affecting the antibody binding site. These conjugates may be used to track immunoglobulins in histochemical, western and ELISA applications. \n\nAlternatively, Protein G may be immobilized onto a solid support to facilitate the purification and recovery of either polyclonal or monoclonal immunoglobulins. \n\nApplications:\nSuitable for use in Immunologically active enzyme conjugates, ELISA, Western blot, Affinity purification of polyclonal and monoclonal antibodies and Immunoprecipitation. Other applications not tested.\n\nActivity:\n(same/more than)95% human IgG binding\n\nMolecular Weight:\n22.6kD. Apparent weight by SDS PAGE is 32kD\n\nExtinction Coefficient: E280(1%) = ~9.5 \n\nStability: pH: 2-10\n\nTemperature: 80 degrees C for 10 min at pH 7.0\n\nIsoelectric Point: \npH 4\n\nAmino Acid Sequence:\nMTYKLILNGKTLKGETTTEAVDAATAEKVFKQYANDNGVDGEWTYDDAT KTFTVTEKPEVIDASELTPAVTTYKLVINGKTLKGETTTEAVDAATAEKVFK QYANDNGVDGEWTYDDATKTFTVTEKPEVIDASELTPAVTTYKLVINGKTL KGETTTKAVDAETAEKAFKQYANDNGVDGVWTYDDATKTFTVTE\n\nStorage and Stability:\nLyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile ddH2O. Aliquot and store at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

P9102-45

Size

1mg

Applications

ELISA, IP, WB

Form

Supplied as a lyophilized powder with no additives. Reconstitute 5mg with 240ul sterile ddH2O.

Purity

(same/more than)95% as determined by SDS-PAGE and RP-HPLC

References

1. Boyle, M.D.P. & Reis, K.J., Biotechnology 5: 697-703 (1987). 2. Fahnestock, S.R., et al., J. Bacteriology 167: 870-877 (1986). 3. Fahnestock, S.R., Trends Biotechnology 5: 79-84 (1987).