Protein–ligand complex structure from serial femtosecond crystallography using soaked thermolysin microcrystals and comparison with structures from synchrotron radiation

Acta Crystallographica Section D: Structural Biology

5 years ago

Protein–ligand complex structure from serial femtosecond crystallography using soaked thermolysin microcrystals and comparison with structures from synchrotron radiation

Rie Tanaka, Makina Yabashi, Michihiro Sugahara, Tomoyuki Tanaka, Takashi Kameshima, Yasumasa Joti, Naoki Kunishima, So Iwata, Takaki Hatsui, Hisashi Naitow, Kensuke Tono, Yoshinori Matsuura, Eriko Nango, Jun Kobayashi

Serial femtosecond crystallography (SFX) with an X-ray free-electron laser is used for the structural determination of proteins from a large number of microcrystals at room temperature. To examine the feasibility of pharmaceutical applications of SFX, a ligand-soaking experiment using thermolysin microcrystals has been performed using SFX. The results were compared with those from a conventional experiment with synchrotron radiation (SR) at 100 K. A protein–ligand complex structure was successfully obtained from an SFX experiment using microcrystals soaked with a small-molecule ligand; both oil-based and water-based crystal carriers gave essentially the same results. In a comparison of the SFX and SR structures, clear differences were observed in the unit-cell parameters, in the alternate conformation of side chains, in the degree of water coordination and in the ligand-binding mode.The applicability of the ligand-soaking method in serial femtosecond crystallography has been examined to examine the feasibility of pharmaceutical applications of X-ray free-electron lasers.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1107/S2059798317008919