ATP binding and hydration state analyses of DAPK. Steps toward neutron protein crystallography studies

In the present study, the hydrated water in the apo form of death-associated protein kinase (DAPK) was analyzed by X-ray crystallography, and crystallization phase diagrams of apo DAPK were obtained at different pH values. Isothermal titration calorimetry demonstrated the DAPK binding mode dependency of binding to ATP analogs. The findings of the present study will be helpful in future neutron protein crystallography studies to determine water orientation during the transfer of a phosphate group from ATP to a target protein. (author)