title: Purification and characterization of a recombinant human IgE Fc epsilon fragment lacking the C4 domain.
abstract: Complementary DNA of human IgE Fc epsilon fragment (residues 226-480) lacking the C epsilon 4 domain was expressed in Escherichia coli and the product was purified by immunoaffinity chromatography on a monoclonal antibody (E12 0.02)-Affi-Gel 10 column. About 1.8 mg of an apparent dimer and 5.9 mg of a monomer were obtained from 65 g E. coli cells with 9.3% recovery. The purified products were found to lack more than half of the COOH-terminal portion of the C epsilon 3 domain. The apparent dimer showed high immunological specific activity (3.6 x 10(6) U/mg protein) comparable to that of natural human IgE when measured by commercial human IgE determination kits.
mesh_terms: D002845:Chromatography; D004247:DNA / Q000235:genetics; D004926:Escherichia coli; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000302:isolation & purification*; D007143:Immunoglobulin Heavy Chains / Q000302:isolation & purification*; D007139:Immunoglobulin epsilon-Chains / Q000235:genetics / Q000302:isolation & purification*; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000302:isolation & purification*
chemical_list: D007141:Immunoglobulin Fc Fragments; D007143:Immunoglobulin Heavy Chains; D007139:Immunoglobulin epsilon-Chains; D011994:Recombinant Proteins; D004247:DNA