Screening a protein array with synthetic biotinylated inorganic polyphosphate to define the human polyP-ome.

Phenotypes are established by thigh regulation on protein functions. This regulation can be mediated allosterically, through protein binding, and covalently, through post-translational modification (PTM). The integration of an ever-increasing number of PTMs into regulatory networks enable and define the proteome complexity. Protein PTMs can occur enzymatically and non-enzymatically. Polyphosphorylation, a recently discovered PTM that belongs to the latter category, is the covalent attachment of the linear ortho-phosphate polymer called inorganic polyphosphate (polyP) to lysine residues. PolyP, which is ubiquitously present in nature, is also known to allosterically control protein function. To date, lack of reagents has prevented the systematic analysis of proteins covalently and/or allosterically associated with polyP. Here we report on the chemical synthesis of biotin-modified monodisperse short chain polyP (bio-polyP8-bio) and its subsequent use to screen a human proteome array to identify proteins that associate with polyP, thereby starting to define the human polyP-ome.