NSRRC Activity Report 2022

122 NSRRC ACTIVITY REPORT 2022 Two workshops were held on the third day. The events are summarized below: Workshop I: Synchrotron for Cross-disciplinary Research in Biology Synchrotron radiation light sources provide unique methods for biomedical studies. This workshop was organized by Dr. Meng-Chiao Ho (Academia Sinica) and Dr. Chun-Jung Chen (NSRRC) and domestic speakers were invited to present their experience in applying synchrotron radiation to their research. This workshop started with Academician Ming-Daw Tsai (Academia Sinica) sharing his exciting discovery of photolyase- catalyzed bond breaking and DNA repair in real time by an X-ray free-electron laser. His team was able to “watch” single- electron photoreduction steps and DNA repair at an atomic resolution, providing some new insights into the enzymatic mechanism of photolyase. Subsequently, Prof. Chun-Hua Hsu (National Taiwan University, NTU) reported the role of the macro domain in ADP-ribose signaling. Prof. Alex Ma (Academia Sinica) introduced the anti-viral lectin he found from a Chinese herb. Using synchrotron X-rays, he resolved the structures of the lectin and the antiviral mechanism by interacting with glycan. The last talk in the morning session was given by the beamline manager, Mr. Chung-Kuang Chou (NSRRC). He introduced the status of the newly opened “TPS 07A Micro-focus X-ray protein crystallography beamline” and helped the attendees to understand the beamline’s capability and user friendliness. The afternoon session started with soft X-ray tomography (SXT). Dr. Hung-Lin Chen (Academia Sinica) shared his finding of a new role of intracellular glycan-galectin-3 aggregation in regulating endosomal signaling using SXT. Prof. Chuang-Rung Chang (NTHU) applied SXT to visualize the mitochondrial network under stress conditions. His preliminary images of yeast mitochondria indicate that altering the balance of mitochondrial dynamics is required for cell survival under environmental stress. Following this, the last three talks were related to X-ray scattering. Prof. Hsiao-Ching Yang (Fu Jen Catholic University) applied medium-angle X-ray/neutron scattering (SAXS/SANS) with a contrast variation technique and high-resolution molecular dynamics simulations to probe the water channel inside the enzymes. Prof. Shih-Che Su (NTHU) combined SAXS, NMR, and cryo-EM techniques to reveal micro and macro structures of chemokine CCL5. Dipeptide repeats (DPR), including poly(GA), poly(GR), poly(GP), poly(PR), and poly(PA) are highly neurotoxic. Prof. Yun-Ru Chen (Academia Sinica) applied wide-angle SAXS to reveal that poly(GA) with fifteen repeats forms flat, ribbon-type fibrils with a characteristic cross-β sheet structure. The workshop was closed and was followed by fruitful discussions among participants and NSRRC staff.