Protein-A/G, His
(a) Analysis by RP-HPLC.
(b) Analysis by SDS-PAGE.
Description
Product Specs
(a) Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) analysis.
(b) Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis.
Product Science Overview
Protein A/G is composed of five IgG-binding regions from Protein A (E, D, A, B, and C) and three from Protein G (C1, C2, and C3). This combination results in a protein with a total of 513 amino acids and a molecular mass of approximately 56.9 kDa . The recombinant protein is produced in Escherichia coli and is fused with a 6×His tag at the C-terminus, which facilitates its purification and detection .
The recombinant Protein A/G has a broader binding capacity compared to either Protein A or Protein G alone. It can bind to various subclasses of human, mouse, and rat IgGs, including human IgG1, IgG2, IgG3, and IgG4; mouse IgG2a, IgG2b, and IgG3; and rat IgG2a and IgG2c . Additionally, it can bind to total IgG from other species such as cow, goat, sheep, horse, rabbit, guinea pig, pig, dog, and cat .
Protein A/G Recombinant, His Tag is widely used for the purification of monoclonal and polyclonal IgG antibodies. The presence of the His tag allows for easy purification using immobilized metal affinity chromatography (IMAC), which exploits the affinity of histidine residues for metal ions like nickel, cobalt, and copper . This method provides a highly efficient means of isolating the recombinant protein from complex mixtures.
The production of His-tagged proteins involves inserting a DNA sequence encoding a string of six to nine histidine residues into the vector used for protein expression. This results in the expression of a recombinant protein with a 6xHis or poly-His tag fused to its N- or C-terminus . The His tag facilitates the purification process, allowing for the specific binding and elution of the protein using metal-chelate supports .
Lyophilized Protein A/G is stable at room temperature for up to three weeks but should be stored desiccated below -18°C for long-term storage . Upon reconstitution, it should be stored at 4°C for short-term use (2-7 days) and below -18°C for long-term use. To prevent degradation, it is recommended to add a carrier protein such as 0.1% human serum albumin (HSA) or bovine serum albumin (BSA) and to avoid repeated freeze-thaw cycles .
