Diversification of polyphosphate end-labeling via bridging molecules

PLoS One. 2020 Aug 21;15(8):e0237849. doi: 10.1371/journal.pone.0237849. eCollection 2020.


Investigation of the biological roles of inorganic polyphosphate has been facilitated by our previous development of a carbodiimide-based method for covalently coupling primary amine-containing molecules to the terminal phosphates of polyphosphate. We now extend that approach by optimizing the reaction conditions and using readily available "bridging molecules" containing a primary amine and an additional reactive moiety, including another primary amine, a thiol or a click chemistry reagent such as dibenzocyclooctyne. This two-step labeling method is used to covalently attach commercially available derivatives of biotin, peptide epitope tags, and fluorescent dyes to the terminal phosphates of polyphosphate. Additionally, we report three facile methods for purifying conjugated polyphosphate from excess reactants.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amines / chemistry*
  • Biotinylation
  • Click Chemistry / methods*
  • Cyclooctanes / chemistry
  • Cystamine / chemistry
  • Fluorescent Dyes / chemistry
  • Hydrogen-Ion Concentration
  • Peptides / chemistry*
  • Polyphosphates / chemistry*
  • Polyphosphates / isolation & purification
  • Sulfhydryl Compounds / chemistry
  • Temperature
  • Time Factors


  • Amines
  • Cyclooctanes
  • Fluorescent Dyes
  • Peptides
  • Polyphosphates
  • Sulfhydryl Compounds
  • Cystamine