The invariant tryptophan in an H chain V region is not essential to antibody binding.

@article{Sharon1988TheIT,
  title={The invariant tryptophan in an H chain V region is not essential to antibody binding.},
  author={Jacqueline Sharon},
  journal={Journal of immunology},
  year={1988},
  volume={140 8},
  pages={2666-9}
}
The first amino acid residue of the second framework region in all antibody H and L chain V regions sequenced to date is invariably tryptophan. To test whether this invariance is essential to proper domain folding and generation of a functional antibody, the tryptophan residue in the heavy chain V region of a mouse anti-p-azophenylarsonate antibody was converted to an alanine residue by oligonucleotide-directed mutagenesis of the H chain gene. The mutant gene was transfected into mouse… CONTINUE READING