Related Experiment Video
Updated: May 31, 2026

Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
TAP-binding peptides prediction by QSAR modeling based on amino acid structural information
Yuanqing Wang1, Xiaoming Cheng, Yong Lin
1Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, P.R. China.
The transporter associated with antigen processing (TAP) is essential for peptide delivery from the cytosol into the lumen of the endoplasmic reticulum (ER), where these peptides are loaded on a major histocompatibility complex (MHC) I molecules and form peptide-MHC complex. The peptide-MHC leaves the ER and displays their antigenic cargo on the cell surface to cytotoxic T cells. In this study, 89 physicochemical properties of amino acid were collected from AAIndex database, and used to characterize the peptides which were binding to TAP. Then, the stepwise regression (STR) was used to optimize the parameters which characterized the TAP binding peptides, and the multiple linear regression (MLR) was used to construct the quantitative structural activity relationship (QSAR) model based on optimized parameters. The quantitative models had good reliability and predictive ability: the Q² of "leave one out" validation is 0.676 and R² of test dataset is 0.722 respectively. Additionally, the standardized coefficients of the models could demonstrate the attributions for each position of epitope and determine which special amino acid is suitable at any position of the peptide. Therefore, the QSAR model constructed by STR-MLR has many advantages, such as, easier calculation and explanation, good performance, and definite physiochemical indication, which could be used to guide the design and modification of the TAP binding peptide.
The transporter associated with antigen processing (TAP) is essential for peptide delivery from the cytosol into the lumen of the endoplasmic reticulum (ER), where these peptides are loaded on a major histocompatibility complex (MHC) I molecules and form peptide-MHC complex. The peptide-MHC leaves the ER and displays their antigenic cargo on the cell surface to cytotoxic T cells. In this study, 89 physicochemical properties of amino acid were collected from AAIndex database, and used to characterize the peptides which were binding to TAP. Then, the stepwise regression (STR) was used to optimize the parameters which characterized the TAP binding peptides, and the multiple linear regression (MLR) was used to construct the quantitative structural activity relationship (QSAR) model based on optimized parameters. The quantitative models had good reliability and predictive ability: the Q² of "leave one out" validation is 0.676 and R² of test dataset is 0.722 respectively. Additionally, the standardized coefficients of the models could demonstrate the attributions for each position of epitope and determine which special amino acid is suitable at any position of the peptide. Therefore, the QSAR model constructed by STR-MLR has many advantages, such as, easier calculation and explanation, good performance, and definite physiochemical indication, which could be used to guide the design and modification of the TAP binding peptide.
Related Concept Videos
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-protein Interfaces
Protein Organization
The primary structure of a protein is its amino acid sequence.
Signal Sequences and Sorting Receptors
The Equilibrium Binding Constant and Binding Strength

