One-pot synthesis of phenylphosphonic acid imprinted polymers for tyrosine phosphopeptides recognition in aqueous phase

The tyrosine phosphorylation of proteins plays a vital role in signal transduction pathways. The highly selective enrichment of tyrosine phosphopeptides remains a significant challenge in this area of research because of the low levels of tyrosine phosphorylation in cells. Herein, we report the development of a novel molecularly imprinted polymer (MIP)-based method for the recognition of tyrosine phosphopeptides in aqueous media using an epitope approach. Phenylphosphonic acid, which has been regarded the “epitope” of phosphotyrosine, was used as a template, and commercially available zinc acrylate was used as a functional monomer to prepare the MIP. The one-pot synthetic process was simple, efficient, and the resulting MIPs were low-cost, robust, and recyclable. The MIP demonstrated significant higher levels of adsorption capacity and selectivity for phenylphosphonic acid than the non-imprinting polymer (NIP) over its structural analog benzoic acid. The MIP was also used as a molecular receptor to recognize tyrosine phosphopeptides in aqueous media, and showed a clear preference for tyrosine phosphopeptides over interfering serine peptides compared to TiO₂. These results revealed the feasibility of the use of MIPs to effectively mimic the epitope approach, and provided a promising alternative to the immunoaffinity techniques commonly used for capturing tyrosine phosphopeptides.