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Generation of Recombinant Human IgG Monoclonal Antibodies from Immortalized Sorted B Cells
Published on: June 5, 2015
Expression of the recombinant human immunoglobulin J chain in Escherichia coli
J Symersky1, J Novak, D T McPherson
1Center for Macromolecular Crystallography, University of Alabama at Birmingham, AL 35294, USA.
Selective transport of polymeric (p) immunoglobulins (Ig) of IgA and IgM isotypes into external secretions by pIg receptor-mediated mechanism depends on the incorporation of joining (J) chain into the polymers. Until now, availability of a free J chain for immunological and biophysical studies has been limited to preparations of denatured J chain forms with moderate yield. Here we report that a recombinant J chain (rJ) can be over-expressed as a soluble fusion protein with thioredoxin using a modified vector pET32 in Escherichia coli. An intact J chain was released by digestion with IgA1 protease from Neisseria gonorrhoeae and isolated in a good yield with immunological and biochemical properties similar to those of J chain obtained by chemical cleavage from pIgA.
Selective transport of polymeric (p) immunoglobulins (Ig) of IgA and IgM isotypes into external secretions by pIg receptor-mediated mechanism depends on the incorporation of joining (J) chain into the polymers. Until now, availability of a free J chain for immunological and biophysical studies has been limited to preparations of denatured J chain forms with moderate yield. Here we report that a recombinant J chain (rJ) can be over-expressed as a soluble fusion protein with thioredoxin using a modified vector pET32 in Escherichia coli. An intact J chain was released by digestion with IgA1 protease from Neisseria gonorrhoeae and isolated in a good yield with immunological and biochemical properties similar to those of J chain obtained by chemical cleavage from pIgA.
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