Molecular mapping of the 8.12 sle-associated idiotype specificity at the single amino acid level
| Autor: | Aideen C. M. Young, Macarena Irigoyen, James C. Sacchettini, Czeslawa Kowal, Betty Diamond |
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| Rok vydání: | 1996 |
| Předmět: |
Idiotype
DNA Mutational Analysis Molecular Sequence Data Immunology Immunoglobulin Variable Region Biology Immunoglobulin light chain Immunoglobulin Idiotypes Immunoglobulin lambda-Chains Antibody Specificity Humans Lupus Erythematosus Systemic Amino Acid Sequence Amino Acids Site-directed mutagenesis Molecular Biology Peptide sequence Gene chemistry.chemical_classification Point mutation Chromosome Mapping Templates Genetic Molecular biology Amino acid chemistry Mutagenesis Site-Directed |
| Zdroj: | Molecular Immunology. 33:1255-1265 |
| ISSN: | 0161-5890 |
| DOI: | 10.1016/s0161-5890(96)00093-4 |
| Popis: | The 8.12 idiotype is expressed in elevated titer in the serum of patients with systemic lupus erythematosus and is a marker for a subpopulation of anti-DNA antibodies that possess a V(lambda)II encoded light chain. This study utilized a eukaryotic expression system to identify the structural basis for expression of this idiotype. Reversion of the 8.12+ DSC light chain to the hslv215.23/DPL11 germline gene reveals that the 8.12 idiotype is encoded in the germline. The 8.12+ DSC and the 8.12 AS17 light chains, both belonging to the V(lambda)II family, were subjected to site directed mutagenesis, to localize amino acids important for expression of the 8.12 idiotype. Point mutations were performed in CDR1, CDR2, FR3 and CDR3, in positions where the 8.12+ DSC differs from the 8.12-AS17. Amino acids in CDR1 and the CDR2 proximal region of FR3, but not the J proximal region of CDR3, play a crucial role in 8.12 reactivity. The 3-D structure of Mcg, a human IgG1, with which DSC shares a sequence homology of 92.3% has been examined to visualize the effect of each of the mutations and to identify the surface on DSC that comprises the idiotype. |
| Databáze: | OpenAIRE |
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