Resolution of hypervariable regions in T-cell receptor beta chains by a modified Wu-Kabat index of amino acid diversity.
AUTOR(ES)
Jores, R
RESUMO
The Wu-Kabat variability coefficient is a well-established descriptor of the susceptibility of an amino acid position to evolutionary replacements. It conveniently highlights stretches of accentuated amino acid variation that, for example, in an antibody molecule account for most of the antigen contacts (complementarity-determining regions). Diverse opinion are held as to why the index yields unclear results when applied instead to the polypeptide sequences of the T-cell antigen receptor. We show that a simple modification enhances the resolving power of the index by increasing the weight on the frequency distribution of the amino acids in the formula. Application of the improved index to T-cell receptor beta chains highlights four unambiguous hypervariable regions, three of which are positioned similar to immunoglobulin complementarity-determining regions along the chain. In a Fab-like three-dimensional model of the T-cell receptor, the four hypervariable regions coincide with the four loops on the surface of the domain and form a contiguous area available for binding.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=55119Documentos Relacionados
- The sizes of the CDR3 hypervariable regions of the murine T-cell receptor beta chains vary as a function of the recombined germ-line segments.
- T-cell receptors from virus-specific cytotoxic T lymphocytes recognizing a single immunodominant nine-amino-acid viral epitope show marked diversity.
- T-cell specific rearrangement of T-cell receptor beta transgenes in mice.
- Chicken T-cell receptor beta-chain diversity: an evolutionarily conserved D beta-encoded glycine turn within the hypervariable CDR3 domain.
- Rearrangement of T-cell receptor beta-chain genes during T-cell development.