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Publication Abstract from PubMed

The T-cell receptor (TCR) recognises peptides bound to major histocompatibility molecules (pMHC) and allows T-cells to interrogate the cellular proteaome for internal anomalies from the cell surface. The TCR contacts both MHC and peptide in an interaction characterised by weak affinity (KD >1 muM). We used phage-display to produce a melanoma-specific TCR (alpha24beta17) with a >30,000-fold enhanced binding affinity (KD = 600 pM) in order to aid our exploration of the molecular mechanisms utilised to maintain peptide specificity. Remarkably, although the enhanced affinity was mediated primarily through new TCR-MHC contacts, alpha24beta17 remained acutely sensitive to modifications at every position along the peptide backbone, mimicking the specificity of the wild type TCR. Thermodynamic analyses revealed an important role for solvation in directing peptide specificity. These findings advance our understanding of the molecular mechanisms that can govern the exquisite peptide specificity characteristic of TCR recognition.

T-cell receptor specificity maintained by altered thermodynamics.,Madura F, Rizkallah PJ, Miles KM, Holland CJ, Bulek AM, Fuller A, Schauenburg AJ, Miles JJ, Liddy N, Sami M, Li Y, Hossain M, Baker BM, Jakobsen BK, Sewell AK, Cole DK J Biol Chem. 2013 May 22. PMID:23698002^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.