APSのアップグレードにより、ある種の抗生物質耐性を理解するための「分子ムービー」が強化される。(APS Upgrade to enhance ​’molecular movies’ to understand certain types of antibiotic resistance)


生体反応をリアルタイムで可視化する新手法を展開 New technique deployed to visualize biological reactions in real time

2023-03-27 アルゴンヌ国立研究所(ANL)



L1メタロβ-ラクタマーゼによるβ-ラクタム切断の時間分解解析 Time-resolved β-lactam cleavage by L1 metallo-β-lactamase

M. Wilamowski,D. A. Sherrell,Y. Kim,A. Lavens,R. W. Henning,K. Lazarski,A. Shigemoto,M. Endres,N. Maltseva,G. Babnigg,S. C. Burdette,V. Srajer & A. Joachimiak
Nature Communications  Published:30 November 2022

figure 1


Serial x-ray crystallography can uncover binding events, and subsequent chemical conversions occurring during enzymatic reaction. Here, we reveal the structure, binding and cleavage of moxalactam antibiotic bound to L1 metallo-β-lactamase (MBL) from Stenotrophomonas maltophilia. Using time-resolved serial synchrotron crystallography, we show the time course of β-lactam hydrolysis and determine ten snapshots (20, 40, 60, 80, 100, 150, 300, 500, 2000 and 4000 ms) at 2.20 Å resolution. The reaction is initiated by laser pulse releasing Zn2+ ions from a UV-labile photocage. Two metal ions bind to the active site, followed by binding of moxalactam and the intact β-lactam ring is observed for 100 ms after photolysis. Cleavage of β-lactam is detected at 150 ms and the ligand is significantly displaced. The reaction product adjusts its conformation reaching steady state at 2000 ms corresponding to the relaxed state of the enzyme. Only small changes are observed in the positions of Zn2+ ions and the active site residues. Mechanistic details captured here can be generalized to other MBLs.