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Publication Abstract from PubMed

Inositol pentakisphosphate 2-kinase catalyzes the phosphorylation of the axial 2-OH of myo-inositol 1,3,4,5,6-pentakisphosphate for de novo synthesis of myo-inositol hexakisphosphate. Disruption of inositol pentakisphosphate 2-kinase profoundly influences cellular processes; from nuclear mRNA export and phosphate homeostasis in yeast and plants, to establishment of left-right asymmetry in zebra fish. We elaborate an active site fluorescent probe that allows high throughput screening of Arabidopsis inositol pentakisphosphate 2-kinase. We show that the probe has a binding constant comparable to the Km values of inositol phosphate substrates of this enzyme, and can be used to prospect for novel substrates and inhibitors of inositol phosphate kinases. We identify several micromolar Ki inhibitors and validate this approach by solving the crystal structure of protein in complex with purpurogallin. We additionally solve structures of protein in complexes with epimeric higher inositol phosphates. This probe may find utility in characterization of a wide family of inositol phosphate kinases.

A Fluorescent Probe Identifies Active Site Ligands of Inositol Pentakisphosphate 2-Kinase.,Whitfield H, Gilmartin M, Baker K, Riley AM, Godage HY, Potter BVL, Hemmings AM, Brearley CA J Med Chem. 2018 Aug 30. doi: 10.1021/acs.jmedchem.8b01022. PMID:30160967^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.