Crystal structure and enzyme activity of DUSP19 with cavity-creating mutations

Abstract

Dual specificity protein tyrosine phosphatases (DUSPs) are important signal transduction enzymes and control activity of various map kinases. DUSP19 belongs to DUSP and is widely distributed in human tissues. Previous studies on the association of DUSP19 with OA have inferred that DUSP19 can be used as an OA therapeutic. Other studies have shown that the activity of proteins can be regulated via cavity-creating mutations. However, detailed understanding of the mechanisms of activity of PTPs is limited. Here, we investigated how the structure of DUSP19 changes when cavity-creating mutation is performed using x-ray crystallography. We determined the crystal structure of DUSP19 L73A at 2.9Å resolution and compared it with the WTDUSP19 structure. We also performed an in vitro enzyme assay to determine if the activity of DUSP19 actually changes due to cavity-creating mutations. As a result of the enzyme assay, mutants of DUSP showed activity increase and decrease by 4.2 times and 0.7 times, respectively. In addition, an enzyme assay experiment using a chemical library was performed to find the chemical that can recover the changed activity again. As a result, we made protein switch by cavity-creating mutation in DUSP19.