FBS Colloquia No.373SANKEN (Institute for Scientific and Industrial Research)

Visualization of enzyme catalytic reaction with mix-and-inject serial crystallography

Enzymes, mainly composed of proteins, are nanomachines that sustain biological activities of living things through efficiently catalyzing chemical reactions at room temperature in the cells. To elucidate the reaction mechanism of the enzymes, it is essential to reveal the atomic structures of several metastable intermediates and their movements during the reaction. To achieve this aim, mix-and-inject serial crystallography (MISC) has been recently developed to visualize them in millisecond range in which the enzyme reaction turns over at room temperature. In MISC, microcrystals of the target enzyme are mixed with substrate solution to generate the reaction intermediates, and the diffraction images by radiation of X-ray free-electron laser (XFEL) are promptly collected at the point where the crystals are serially ejected. The present study revealed the details of movements of the enzyme active site along the reaction coordinate using the target enzyme copper amine oxidase in millisecond range. These basic studies of enzymes reaction are applicable to various studies including drug development and design of useful enzymes. Recent progress will be introduced in this seminar.