Immunoglobulins recombinant proteins

Recombinant Protein G from cell lysates of E. coli Semi-preparative purification Affinity (human immunoglobulin G) disks [74]... 

Other common impurities, such as immunoglobulins and protein A, result from the immunoaffinity purification of recombinant proteins or MAbs.16 If affinity chromatography is used to purify an antigen, then an ELISA can be used to detect contaminating levels of MAbs leached from the column. An assay for the antibody needs to detect the antibody in the presence and absence of its specific antigen. 

Attachment via affinity interactions. These methods are based on the high affinity of Fc receptors, such as protein A (PrA), protein G (PrG) or recombinant protein A/G, for the amino groups in the Fc region of antibodies. In these procedures, the Fc receptor is immobilized on a solid support and is the key element for the oriented immobilization of the antibody (Fig. 5b). However, not all Fc receptors have the same affinity to all IgG isotypes. PrA has been successfully used to bind the Fc portion of antibodies from many mammalian species, except for goat, sheep, cow and horse. PrG has some advantages over protein A, as it reacts with more IgG isotypes and to a lower extent with other immunoglobulins, such as human IgM and IgA. How-... 

Another application shows the preparative purification and polishing of a therapeutic fusion protein with a humanized recombinant IgG protein. The fusion protein was expressed by the fermentation of baby hamster kidney cells. The filtered culture supernatant (155 liters) contained 2.2 g of IgG and 75.5 g of total protein. After the immunoglobulins were isolated by expanded bed adsorption and rebuffering, the IgG fraction was bound to Fractogel EMD SOj (M). This column achieved baseline separation of complete antibodies (fusion protein) from small amounts of antibodies lacking the fusion part. The resulting highly purified IgG fraction (110 ml) was diluted to 150 ml and... 

Stevens PW, Raffen R, Hanson DK, Deng YL, Berrios Hammond M, Westholm FA, Murphy C, Eulitz M, Wetzel R, Solomon A, et al. Recombinant immunoglobulin variable domains generated from synthetic genes provide a system for in vitro characterization of light-chain amyloid proteins. Protein Sci 1995 4 421-432. 

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