TRACKING ATP-DEPENDENT PROTEIN DYNAMICS

Adenosine triphosphate (ATP) drives many critical cellular processes. We will use laser-induced release from a caged, inactive form of ATP followed by short X-ray pulses at the dedicated time-resolved X-ray solution scattering (TR-XSS) beamline ID09 at ESRF-EBS to study protein conformational change in real time. We aim to track domain movements involved in regulation of membrane protein transporters critical to human health. The pump-and-probe methodology will determine: 1.) kinetics and structural dynamics of a human Ca2+ ATPase that regulates beating of the heart; 2.) lipid regulatory effects on domain movements in Ca2+ transport; 3.) structural dynamics of regulatory internal domains in Cu+ transport. The results will provide better understanding of membrane transport regulation and cooperative dynamics in biologically important proteins, and significantly increase the number of protein targets for similar time-resolved X-ray studies.