Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior

<p>Abstract</p> <p>Background</p> <p>Experts in peptide:MHC binding studies are often able to estimate the impact of a single residue substitution based on a heuristic understanding of amino acid similarity in an experimental context. Our aim is to quantify this measure...

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Main Authors: Sette Alessandro, Pinilla Clemencia, Sidney John, Kim Yohan, Peters Bjoern
Format: Article
Language:English
Published: BMC 2009-11-01
Series:BMC Bioinformatics
Online Access:http://www.biomedcentral.com/1471-2105/10/394
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author Sette Alessandro
Pinilla Clemencia
Sidney John
Kim Yohan
Peters Bjoern
author_facet Sette Alessandro
Pinilla Clemencia
Sidney John
Kim Yohan
Peters Bjoern
author_sort Sette Alessandro
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Experts in peptide:MHC binding studies are often able to estimate the impact of a single residue substitution based on a heuristic understanding of amino acid similarity in an experimental context. Our aim is to quantify this measure of similarity to improve peptide:MHC binding prediction methods. This should help compensate for holes and bias in the sequence space coverage of existing peptide binding datasets.</p> <p>Results</p> <p>Here, a novel amino acid similarity matrix (PMBEC) is directly derived from the binding affinity data of combinatorial peptide mixtures. Like BLOSUM62, this matrix captures well-known physicochemical properties of amino acid residues. However, PMBEC differs markedly from existing matrices in cases where residue substitution involves a reversal of electrostatic charge. To demonstrate its usefulness, we have developed a new peptide:MHC class I binding prediction method, using the matrix as a Bayesian prior. We show that the new method can compensate for missing information on specific residues in the training data. We also carried out a large-scale benchmark, and its results indicate that prediction performance of the new method is comparable to that of the best neural network based approaches for peptide:MHC class I binding.</p> <p>Conclusion</p> <p>A novel amino acid similarity matrix has been derived for peptide:MHC binding interactions. One prominent feature of the matrix is that it disfavors substitution of residues with opposite charges. Given that the matrix was derived from experimentally determined peptide:MHC binding affinity measurements, this feature is likely shared by all peptide:protein interactions. In addition, we have demonstrated the usefulness of the matrix as a Bayesian prior in an improved scoring-matrix based peptide:MHC class I prediction method. A software implementation of the method is available at: <url>http://www.mhc-pathway.net/smmpmbec</url>.</p>
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spelling doaj.art-125b4323c61f45dda337138e55fbcb462022-12-22T03:12:02ZengBMCBMC Bioinformatics1471-21052009-11-0110139410.1186/1471-2105-10-394Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian priorSette AlessandroPinilla ClemenciaSidney JohnKim YohanPeters Bjoern<p>Abstract</p> <p>Background</p> <p>Experts in peptide:MHC binding studies are often able to estimate the impact of a single residue substitution based on a heuristic understanding of amino acid similarity in an experimental context. Our aim is to quantify this measure of similarity to improve peptide:MHC binding prediction methods. This should help compensate for holes and bias in the sequence space coverage of existing peptide binding datasets.</p> <p>Results</p> <p>Here, a novel amino acid similarity matrix (PMBEC) is directly derived from the binding affinity data of combinatorial peptide mixtures. Like BLOSUM62, this matrix captures well-known physicochemical properties of amino acid residues. However, PMBEC differs markedly from existing matrices in cases where residue substitution involves a reversal of electrostatic charge. To demonstrate its usefulness, we have developed a new peptide:MHC class I binding prediction method, using the matrix as a Bayesian prior. We show that the new method can compensate for missing information on specific residues in the training data. We also carried out a large-scale benchmark, and its results indicate that prediction performance of the new method is comparable to that of the best neural network based approaches for peptide:MHC class I binding.</p> <p>Conclusion</p> <p>A novel amino acid similarity matrix has been derived for peptide:MHC binding interactions. One prominent feature of the matrix is that it disfavors substitution of residues with opposite charges. Given that the matrix was derived from experimentally determined peptide:MHC binding affinity measurements, this feature is likely shared by all peptide:protein interactions. In addition, we have demonstrated the usefulness of the matrix as a Bayesian prior in an improved scoring-matrix based peptide:MHC class I prediction method. A software implementation of the method is available at: <url>http://www.mhc-pathway.net/smmpmbec</url>.</p>http://www.biomedcentral.com/1471-2105/10/394
spellingShingle Sette Alessandro
Pinilla Clemencia
Sidney John
Kim Yohan
Peters Bjoern
Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
BMC Bioinformatics
title Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
title_full Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
title_fullStr Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
title_full_unstemmed Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
title_short Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior
title_sort derivation of an amino acid similarity matrix for peptide mhc binding and its application as a bayesian prior
url http://www.biomedcentral.com/1471-2105/10/394
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