Multiplexed quantitation of protein expression and phosphorylation based on functionalized soluble nanopolymers

J Am Chem Soc. 2012 Nov 7;134(44):18201-4. doi: 10.1021/ja308453m. Epub 2012 Oct 24.


We report here for the first time the multiplexed quantitation of phosphorylation and protein expression based on a functionalized soluble nanopolymer. The soluble nanopolymer, pIMAGO, is functionalized with Ti (IV) ions for chelating phosphoproteins in high specificity and with infrared fluorescent tags for direct, multiplexed assays. The nanopolymer allows for direct competition for epitopes on proteins of interest, thus facilitating simultaneous detection of phosphorylation by pIMAGO and total protein amount by protein antibody in the same well of microplates. The new strategy has a great potential to measure cell signaling events by clearly distinguishing actual phosphorylation signals from protein expression changes, thus providing a powerful tool to accurately profile cellular signal transduction in healthy and disease cells. We anticipate broad applications of this new strategy in monitoring cellular signaling pathways and discovering new signaling events.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibodies / immunology
  • Cell Line
  • Dendrimers / chemistry
  • Fluorescent Dyes / chemistry*
  • Fungal Proteins / analysis
  • Fungal Proteins / immunology
  • Humans
  • Immunoassay
  • Intracellular Signaling Peptides and Proteins / analysis
  • Intracellular Signaling Peptides and Proteins / immunology
  • Nanostructures / chemistry*
  • Phosphoproteins / analysis*
  • Phosphoproteins / immunology
  • Phosphorylation
  • Polymers / chemistry*
  • Protein-Tyrosine Kinases / analysis
  • Protein-Tyrosine Kinases / immunology
  • Syk Kinase
  • Titanium / chemistry*
  • Yeasts / chemistry


  • Antibodies
  • Dendrimers
  • Fluorescent Dyes
  • Fungal Proteins
  • Intracellular Signaling Peptides and Proteins
  • Phosphoproteins
  • Polymers
  • Titanium
  • Protein-Tyrosine Kinases
  • SYK protein, human
  • Syk Kinase