Altering the Peptide Binding Selectivity of Polymeric Reverse Micelle Assemblies via Metal Ion Loading

Abstract

Supramolecular reverse micelle assemblies, formed by amphiphilic copolymers, can selectively encapsulate molecules in their interiors depending on the functional groups present in the polymers. Altering the binding selectivity of these materials typically requires the synthesis of alternate functional groups. Here, we demonstrate that the addition of Zr(IV) ions to the interiors of reverse micelles having phosphonate functional groups transforms the supramolecular materials from ones that selectively bind positively charged peptides into materials that selectively bind phosphorylated peptides. We also show that the binding selectivity of these reverse micelle assemblies can be further tuned by varying the fractions of phosphonate groups in the copolymer structure. The optimized reverse micelle materials can selectively transfer and bind phosphorylated peptides from aqueous solutions over a wide range of pH conditions and can selectively enrich phosphorylated peptides even in complicated mixtures.

Polymeric nanoassemblies for enrichment and detection of peptides and proteins in human breast milk

“…Our amphiphilic polymers are unique in that t h e y s e l f -a s s e m b l e i n t o r e v e r s e m i c e l l e -t y p e nanoassemblies in apolar solvents and sequester targeted peptides or proteins based on their isoelectric points (pI) [30][31][32]. High enrichment selectivity and capacity can be easily achieved by tuning the functional groups on the polymers and varying the extraction conditions [33][34][35]. Moreover, these materials are easy to synthesize, low-cost, and highly stable as compared with current antibody-based enrichment reagents.…”

Improved mass spectrometric detection of acidic peptides by variations in the functional group pKa values of reverse micelle extraction agents

“…38 We have also shown that materials containing positively-charged functional groups or metal-bound functional groups can selectively extract and sensitively detect negatively-charged peptides and phosphorylated peptides, respectively. 39–40…”