Substrate promiscuity of inositol 1,4,5-trisphosphate kinase driven by structurally-modified ligands and active site plasticity.

ABSTRACT: D-myo-inositol 1,4,5-trisphosphate (InsP₃) is a fundamental second messenger in cellular Ca²⁺ mobilization. InsP₃ 3-kinase, a highly specific enzyme binding InsP₃ in just one mode, phosphorylates InsP₃ specifically at its secondary 3-hydroxyl group to generate a tetrakisphosphate. Using a chemical biology approach with both synthetised and established ligands, combining synthesis, crystallography, computational docking, HPLC and fluorescence polarization binding assays using fluorescently-tagged InsP₃, we have surveyed the limits of InsP₃ 3-kinase ligand specificity and uncovered surprisingly unforeseen biosynthetic capacity. Structurally-modified ligands exploit active site plasticity generating a helix-tilt. The

SUBMITTER: Marquez-Monino MA 

PROVIDER: S-EPMC10876669 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature