Abstract |
We determined the crystal structures of the T cell receptor (TCR)-like antibody 25-D1.16 Fab fragment bound to a complex of SIINFEKL peptide from ovalbumin and the H-2K(b) molecule. Remarkably, this antibody directly "reads" the structure of the major histocompatibility complex (MHC)-bound peptide, employing the canonical diagonal binding mode utilized by most TCRs. This is in marked contrast with another TCR-like antibody, Hyb3, bound to melanoma peptide MAGE-A1 in association with HLA-A1 MHC class I. Hyb3 assumes a non-canonical orientation over its cognate peptide-MHC and appears to recognize a conformational epitope in which the MHC contribution is dominant. We conclude that TCR-like antibodies can recognize MHC-bound peptide via two different mechanisms: one is similar to that exploited by the preponderance of TCRs and the other requires a non-canonical antibody orientation over the peptide-MHC complex.
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Authors | Tatiana Mareeva, Erik Martinez-Hackert, Yuri Sykulev |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 283
Issue 43
Pg. 29053-9
(Oct 24 2008)
ISSN: 0021-9258 [Print] United States |
PMID | 18703505
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Epitopes
- Immunoglobulin Fab Fragments
- Peptides
- Receptors, Antigen, T-Cell
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Topics |
- Crystallography, X-Ray
- Epitopes
(chemistry)
- Immunoglobulin Fab Fragments
(chemistry)
- Major Histocompatibility Complex
- Models, Biological
- Models, Molecular
- Molecular Conformation
- Peptides
(chemistry)
- Protein Conformation
- Receptors, Antigen, T-Cell
(immunology, metabolism)
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