Figure 2.

Analysis, by SDS–polyacrylamide slab gel electrophoresis under reducing conditions, of ³⁵S-labelled DNP-binding antibody produced by transfected and untransfected cell lines. X-10 is the parental cell line producing κ chains only, and Sp6 is the parental cell line producing both κ-and wild-type mouse μ-chains. Other lanes show the analysis of mutant mouse antibody produced by transfection of X-10 cells with a mouse μ gene in which the C-terminal sequence has been altered. The name of the species from which the introduced μ-chain C-terminal sequence was taken (Table 2) is indicated above the lanes. The presence of Cys or Ser at position 414 of the μ-chain is also indicated above each lane. The positions of standards (phosphorylase b, serum albumin, ovalbumin, carbonic anhydrase and trypsin inhibitor) are shown by arrows.