Some observations on the replacement of the conserved amino acid residues of immunoglobulin domains.
1. Computer graphics have been used to model replacements of conserved residues in immunoglobulin domains. 2. Replacements, even those involving large changes in side chain volume, could be accommodated in the domain but rotation and repacking of surrounding side chains was generally necessary. 3. Repacking often resulted in increases in inter-atomic distances between side chains and loss of some van der Waals' contacts. This would be expected to make the domain slightly less stable. 4. Losses in domain stability might not have a serious affect on antigen binding but could result in circulating antibody becoming more susceptible to biological degradation with considerable reduction in biological half-life.
Beale
D
D
Agricultural and Food Research Council, Institute of Animal Physiology and Genetics Research, Babraham, Cambs, England.
Coadwell
J
J
D000409:Alanine; D000596:Amino Acids; D003196:Computer Graphics; D003545:Cysteine; D007127:Immunoglobulin Constant Regions; D007135:Immunoglobulin Variable Region; D007136:Immunoglobulins; D007930:Leucine; D012694:Serine; D014364:Tryptophan; D014443:Tyrosine; D001613:beta 2-Microglobulin
D000596:Amino Acids; D007127:Immunoglobulin Constant Regions; D007135:Immunoglobulin Variable Region; D007136:Immunoglobulins; D001613:beta 2-Microglobulin; D014443:Tyrosine; D012694:Serine; D014364:Tryptophan; D007930:Leucine; D003545:Cysteine; D000409:Alanine