Abstract 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 Zn 2+ 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 Zn 2+ ions and the active site residues. Mechanistic details captured here can be generalized to other MBLs.
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Quantum entanglement involving coherent superpositions of macroscopically distinct states is among the most striking features of quantum theory, but its realization is challenging because such states are extremely fragile. Using a programmable quantum simulator based on neutral atom arrays with interactions mediated by Rydberg states, we demonstrate the creation of “Schrödinger cat” states of the Greenberger-Horne-Zeilinger (GHZ) type with up to 20 qubits. Our approach is based on engineering the energy spectrum and using optimal control of the many-body system. We further demonstrate entanglement manipulation by using GHZ states to distribute entanglement to distant sites in the array, establishing important ingredients for quantum information processing and quantum metrology.more » « less
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Abstract The exclusive photoproduction of $$\mathrm {\Upsilon }\mathrm {(nS)} $$ Υ ( nS ) meson states from protons, $$\gamma \mathrm {p} \rightarrow \mathrm {\Upsilon }\mathrm {(nS)} \,\mathrm {p}$$ γ p → Υ ( nS ) p (with $$\mathrm {n}=1,2,3$$ n = 1 , 2 , 3 ), is studied in ultraperipheral $$\mathrm {p}$$ p Pb collisions at a centre-of-mass energy per nucleon pair of $$\sqrt{\smash [b]{s_{_{\mathrm {NN}}}}} = 5.02\,\text {TeV} $$ s NN = 5.02 TeV . The measurement is performed using the $$\mathrm {\Upsilon }\mathrm {(nS)} \rightarrow \mu ^+\mu ^-$$ Υ ( nS ) → μ + μ - decay mode, with data collected by the CMS experiment corresponding to an integrated luminosity of 32.6 $$\,\text {nb}^{-1}$$ nb - 1 . Differential cross sections as functions of the $$\mathrm {\Upsilon }\mathrm {(nS)} $$ Υ ( nS ) transverse momentum squared $$p_{\mathrm {T}} ^2$$ p T 2 , and rapidity y , are presented. The $$\mathrm {\Upsilon (1S)}$$ Υ ( 1 S ) photoproduction cross section is extracted in the rapidity range $$|y |< 2.2$$ | y | < 2.2 , which corresponds to photon–proton centre-of-mass energies in the range $$91
