Investigation of interaction between CDK inhibitor ZK243919 and human pyridoxal kinase (PDXK) by chemical proteomics

摘要

Chemical Proteomics is used to gain binding profiles of small molecule inhibitors (1). The ligands are immobilized on a suitable matrix and inhibitor affinity chromatography (IAC) is performed, followed by MS analysis of enriched proteins. The CDK2 inhibitor (R)-roscovitine (CYC202/Seliciclib) was shown to bind to pyridoxal kinase (PDXK) (2). PDXK is a non-protein kinase responsible for activation of vitamin B6 (pyridoxal). Interaction with (R)-roscovitine occurs by binding to the pyridoxal binding site rather than the ATP site. To address the question whether other CDK-inhibitors might also bind to the PDXK, we performed chemical proteomics experiments using the high affinity CDK inhibitor ZK243919 (3). Since a specific interaction was found, PDXK activity assays were carried out in order to quantify the PDXK/ZK243919 binding affinity.