Immunoaffinity isolation of modified peptides from complex mixtures

摘要

The invention is a method for isolating a target population of naturally-occurring post-translationally modified peptides from a complex mixture of peptides, said method comprising the steps of: (a) obtaining a digested proteinaceous preparation from an organism, wherein said digested proteinaceous preparation comprises a complex mixture of peptides comprising naturally-occurring post-translationally modified peptides from two or more different proteins and further fractionating said post-translationally modified peptides in said digested proteinaceous preparation by reverse-phased chromatography to produce a fractionated proteinaceous preparation; (b) contacting said fractionated proteinaceous preparation with at least one immobilized post-translational modification-specific antibody; and (c) isolating said target of naturally-occurring post-translationally modified peptides specifically bound by said immobilized modification-specific antibody in step (b).