title: Synthesis of part of a mouse immunoglobulin light chain in a bacterial clone.
abstract: We have cloned double stranded cDNA sequences encoding a mouse immunoglobulin light chain (L-321) into the PstI site of the beta-lactamase gene of plasmid pBR322 by the oligo (dG)-oligo (dC) tailing procedure. Escherichia coli X1776 transformed by the recombinant plasmids were screened for the expression of L-321 antigenic determinants by a newly developed in situ radio-immunoassay. One out of seven transformants screened was found to synthesize an L-chain like protein. Each bacterial cell produces about 550 molecules of the L-chain sequence. Preferential segregation of the L-chain sequence to the periplasmic space suggest covalent attachment of the L-chain sequence to the N-terminal portion of beta-lactamase. Restriction mapping of the plasmid DNA isolated from the positive clone indicated the presence of a DNA sequence coding for the entire constant region and extending into the variable region for a length corresponding to about 40 amino acid residues. The orientation of the cloned cDNA with respect to the plasmid DNA is compatible with the formation of a fused beta-lactamase-L-321 peptide.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004274:DNA, Recombinant / Q000276:immunology*; D000939:Epitopes; D004926:Escherichia coli / Q000276:immunology; D005802:Genes, MHC Class II; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D008722:Methods; D051379:Mice
chemical_list: D004274:DNA, Recombinant; D000939:Epitopes; D007147:Immunoglobulin Light Chains