Method for constructing a novel affinity peptide library for binding immunoglobulin g based on a protein affinity model of protein a

Abstract

An affinity ligand peptide library of IgG constructed on the basis of Protein A affinity model and the application of a design method thereof. According to the Molecular Mechanics—Poisson-Boltzmann surface area (MM/PBSA) method and on the basis of the known human IgG-Protein A complex structure, the hot spots of Protein A that have high affinity for human IgG are obtained analytically, and a Protein A simplified affinity model is built thereof. An affinity peptide library of IgG is constructed including heptapeptide and octapeptide structural modes. On the basis of the peptide structural modes, the types of inserted amino acids that 'X' residues represent are further identified using amino acid location method. Then, molecular docking and molecular dynamics simulation methods are used to screen the candidate peptides successively. Finally, the affinity peptide ligands that can effectively purify IgG are identified using affinity chromatography.