Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

A 13C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical VH, VL, and CL domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with 13C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with [1-13C]Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how 13C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule