Detection of Proteins like Human $\gamma $ and $\beta $ Globins in Escherichia coli Carrying Recombinant DNA Plasmids

Escherichia coli strain $\chi $1776 carrying recombinant DNA plasmids containing cDNA copies of human $\beta $ or $\gamma $ globin mRNAs has been shown by radioimmunoassay to synthesize polypeptides antigenically related to the $\beta $ and $\gamma $ chains of human hemoglobin. The $\gamma $ and $\beta $ polypeptides have been enriched from lysates on immunoabsorbent columns containing hemoglobin antibodies and shown to specifically inhibit the antigen-antibody binding between $^{125}$I-labeled hemoglobin and the homologous antibody but not other hemoglobin-antihemoglobin reactions. Clone JW151, which is known to contain a complete copy of the coding portion of the $\gamma $ globin mRNA, has been shown to produce a protein that reacts specifically with antibody to the $\gamma $ chain of fetal hemoglobin, hemoglobin Kenya, and hemoglobin Bart's.