Article
Chemistry, Multidisciplinary
Anna L. Poptic, Jeffrey K. Klinger, Samantha L. Carter, Curtis E. Moore, Shiyu Zhang
Summary: In this study, a new diiron complex was synthesized to mimic the electron-poor coordination environment of Mka-HLP, successfully reproducing the nitric oxide oxidase reactivity. The results suggest the presence of an intermediacy of {FeNO}(6)/{FeNO}(7) species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Gabriela C. Schroder, William B. O'Dell, Simon P. Webb, Pratul K. Agarwal, Flora Meilleur
Summary: Metalloproteins catalyze redox reactions using their metallocofactors. Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that degrade recalcitrant polysaccharides. Neutron protein crystallography reveals the initial steps of oxygen activation in Neurospora crassa LPMO9D, with His157 identified as the proton donor. His1 and His161 also display conformational flexibility.
Article
Chemistry, Multidisciplinary
Cejun Hu, Yanfang Hu, Aonan Zhu, Mingming Li, Junli Wei, Yuying Zhang, Wei Xie
Summary: This review summarizes advances in identifying active sites and capturing catalytic surface intermediates, and highlights how structural evolution on 2D materials affects catalytic activity. The importance of developing new in situ techniques and electrokinetic analysis methods is emphasized.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Danushka M. Ekanayake, Dao Pham, Andrew L. Probst, Joshua R. Miller, Codrina V. Popescu, Adam T. Fiedler
Summary: The activation of O-2 at thiolate-ligated iron sites is crucial for the function of metalloenzymes and synthetic catalysts. In this study, mononuclear nonheme iron-thiolate complexes were prepared as models for substrate-bound enzymes EgtB and OvoA, showing reactivity with O-2 to form metastable intermediates. Characterization and computational modeling of these intermediates provide insights into the unique spectral features and reaction landscapes of iron-thiolate species, aiding in the identification of reaction intermediates in biological and synthetic environments.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Pokhraj Ghosh, Molly Stauffer, Valiallah Hosseininasab, Subrata Kundu, Jeffery A. Bertke, Thomas R. Cundari, Timothy H. Warren
Summary: Copper nitrite reductases convert nitrite ions to nitric oxide and nitrous oxide at high levels of nitrogen oxide flux. The assembly of nitric oxide at a single copper site to form copper cis-hyponitrites has been demonstrated in the presence of an external reductant. Furthermore, the removal of a fraction of the structure in the copper cis-hyponitrite complex can be achieved by adding specific reagents, resulting in the formation of a spectroscopically similar anion. These studies provide insights into the reductive coupling of nitrogen oxides at a single copper center and the utilization of the strong oxidizing power of nitrite.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Hang Zhang, Tao Luo, Yan Long, Yingkang Chen, Junwei Fu, Hui Liu, Junhua Hu, Zhang Lin, Liyuan Chai, Min Liu
Summary: This study demonstrates that three-coordinated aluminum is the dominant active site for the hydrolytic decomposition of CF4, supported by experimental and computational evidence. This finding is of significance for reducing CF4 emissions and mitigating global warming.
ENVIRONMENTAL SCIENCE-NANO
(2022)
Article
Chemistry, Inorganic & Nuclear
Silvia Schoch, Simona Braccini, Lorenzo Biancalana, Alessandro Pratesi, Tiziana Funaioli, Stefano Zacchini, Guido Pampaloni, Federica Chiellini, Fabio Marchetti
Summary: In this study, a series of cationic triiron complexes resulting from the conjugation of ferrocenyl skeleton with a diiron bis-cyclopentadienyl core were synthesized and their cytotoxicity on cancer cell lines and non-tumoral cells was evaluated. The results showed that most of the cationic complexes exhibited low toxicity in cancer cells and non-tumoral cells.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
June Sung Lim, Jae Hyung Kim, Jinwoo Woo, Du San Baek, Kyuwook Ihm, Tae Joo Shin, Young Jin Sa, Sang Hoon Joo
Summary: The study found that the carboxyl group at the edge sites of graphitic carbons is the primary active site for the 2e ORR, while the carbonyl group is a secondary active site. The nanoporous carbon catalyst with abundant active edge sites and optimized structure exhibited the highest H2O2 electrosynthesis activity and excellent long-term stability.
Article
Chemistry, Multidisciplinary
Panpan Li, Zhaoyu Jin, Zhiwei Fang, Guihua Yu
Summary: The necessity for sustainable ammonia production using economic and environment-friendly technologies is increasing globally. This study presents an iron-based single-atom catalyst with uniform atomic dispersion on carbon, which exhibits high NH3 yield rate and faradaic efficiency. The catalyst's high selectivity for NH3 is attributed to the unique electronic structures of the individual Fe sites.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Chemistry, Organic
Bat-El Oded, Yael Diskin-Posner, Vered Marks, Haya Kornweitz, Flavio Grynszpan
Summary: Theoretical and experimental approaches were combined to study the mechanism behind the formation of bimanes. The results supported the proposed mechanism and identified a crucial intermediate. The unexpected generation of an unsymmetrical bimane compound was also discovered, requiring further investigation.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Kazuhiro Yamada, Johnny Mendoza, Markos Koutmos
Summary: MTHFR is a flavoprotein that catalyzes the transfer of a methyl group from the folate cycle to the methionine cycle. It shows pH-dependent inhibition by a substrate analog. The protein undergoes conformational changes to accommodate different substrates, providing insights into its functional relevance.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Michel A. Struwe, Palraj Kalimuthu, Zhenyao Luo, Qifeng Zhong, Daniel Ellis, Jing Yang, K. C. Khadanand, Jeffrey R. Harmer, Martin L. Kirk, Alastair G. McEwan, Bernd Clement, Paul Bernhardt, Bostjan Kobe, Ulrike Kappler
Summary: MtsZ is a molybdenum-containing methionine sulfoxide reductase that supports virulence in the human respiratory pathogen Haemophilus influenzae. The crystal structure of HiMtsZ revealed a previously unrecognized substrate-binding region that explains diverse substrate specificity. Flexibility in the electronic structure of the Mo centers is apparent in two of the three HiMtsZ EPR-active Mo(V) species being catalytically incompetent off-pathway forms.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Eleonora Romeo, Maria Fernanda Lezana-Muralles, Francesc Illas, Federico Calle-Vallejo
Summary: The electrocatalytic reduction of oxidized nitrogen compounds (NOx) is important for rebalancing the nitrogen cycle. This study explores the use of catalytic matrices to extract features of active transition metal catalysts for NO electroreduction. The matrices reveal that active catalysts stabilize *NHO over *NOH and have undercoordinated sites, indicating their potential in NOx electroreduction.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Ryan P. Sweeney, Phillip M. Danby, Andreas Geissner, Ryan Karimi, Jesper Brask, Stephen G. Withers
Summary: Efforts have been made to find better amylase mutants through high-throughput screening, aided by the development of efficient active site titration reagents for quantitation of active mutants in crude cell lysates. The designed reagent incorporates a highly reactive fluorogenic leaving group onto unsaturated cyclitol ethers, providing a convenient titrant for alpha-amylases down to low nanomolar levels.
Article
Engineering, Chemical
Junao Zhu, Zhirong Yang, Yuanhan Chen, Mingming Chen, Zhen Liu, Yueqiang Cao, Jing Zhang, Gang Qian, Xinggui Zhou, Xuezhi Duan
Summary: A mechanistic understanding of the active intermediates in the dinitration of 2,6-diaminopyridine (DAP) in the nitric-sulfuric acid system is crucial for controlling the selectivity of the target product, 2,6-diamino-3,5-dinitropyridine (DADNP). The study proposes the HSO4--NO2+ complex as the dominant active nitrating intermediate, with a low energy barrier for direct dinitration. The presence of water leads to the formation of less active complexes and the sulfonation of DAP, resulting in the formation of mononitration byproduct. Thermal effects generate an undesirable pyridine-NHNO2 intermediate, inhibiting the reaction and reducing DAP conversion. Experimental confirmation highlights the importance of eliminating thermal effects and controlling water content.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Inorganic & Nuclear
Andrew C. Weitz, Matthew R. Mills, Alexander D. Ryabov, Terrence J. Collins, Yisong Guo, Emile L. Bominaar, Michael P. Hendrich
INORGANIC CHEMISTRY
(2019)
Article
Multidisciplinary Sciences
Kimberly Rizzolo, Steven E. Cohen, Andrew C. Weitz, Madeline M. Lopez Munoz, Michael P. Hendrich, Catherine L. Drennan, Sean J. Elliott
NATURE COMMUNICATIONS
(2019)
Review
Biochemistry & Molecular Biology
Jonathan D. Caranto
CURRENT OPINION IN CHEMICAL BIOLOGY
(2019)
Article
Biochemistry & Molecular Biology
Sinjinee Sardar, Andrew Weitz, Michael P. Hendrich, Brad S. Pierce
Article
Biochemistry & Molecular Biology
Jiafeng Geng, Andrew C. Weitz, Kednerlin Dornevil, Michael P. Hendrich, Aimin Liu
Article
Chemistry, Inorganic & Nuclear
Andrew C. Weitz, Saborni Biswas, Kim Rizzolo, Sean Elliott, Emile L. Bominaar, Michael P. Hendrich
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Kimberly Rizzolo, Andrew C. Weitz, Steven E. Cohen, Catherine L. Drennan, Michael P. Hendrich, Sean J. Elliott
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Multidisciplinary
Victoria F. Oswald, Justin L. Lee, Saborni Biswas, Andrew C. Weitz, Kaustuv Mittra, Ruixi Fan, Jikun Li, Jiyong Zhao, Michael Y. Hu, Esen E. Alp, Emile L. Bominaar, Yisong Guo, Michael T. Green, Michael P. Hendrich, A. S. Borovik
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Biochemistry & Molecular Biology
Christopher P. Martin, Manyun Chen, Maria F. Martinez, Yousong Ding, Jonathan D. Caranto
Summary: TxtE is involved in NO-dependent Trp nitration, and the resistance of the intermediate to reduction is a key feature, allowing efficient nitration activity.
Article
Biochemistry & Molecular Biology
Zhongxin Ma, Ashley A. Holland, Ilana Szlamkowicz, Vasileios Anagnostopoulos, Maria Luiza Caldas D. Nogueira, Jonathan D. L. Caranto, Victor Davidson
Summary: The hemerythrin-like protein from Mycobacterium kansasii (Mka HLP) is a unique oxo-bridged diiron protein found only in mycobacterial species that cause respiratory disorders in humans. The study reveals that Mka HLP exhibits catalase activity and undergoes changes in absorbance when exposed to nitric oxide (NO). It is shown that Mka HLP can convert NO to nitrite (NO2-) and nitrate (NO3-), and also exhibits NO peroxidase activity. These findings highlight the important role of Mka HLP in deterring nitrosative stress and adapting to hypoxic conditions.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2022)
Article
Biotechnology & Applied Microbiology
Kara A. Strickland, Ashley A. Holland, Alan Trudeau, Ilana Szlamkowicz, Melanie J. Beazley, Vasileios A. Anagnostopoulos, David E. Graham, Jonathan D. Caranto
Summary: The study demonstrates that NnlA does not require nonheme iron but needs heme cofactor reduction to activate the degradation of NNG. NnlA is a homodimeric heme-binding PAS domain protein.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Chemistry, Inorganic & Nuclear
Wesley J. Transue, Rae Ana Snyder, Jonathan D. Caranto, Donald M. Kurtz Jr, Edward I. Solomon
Summary: This paper describes a particle swarm optimization (PSO) algorithm for fitting ground-state spin Hamiltonian parameters from variable-temperature/variable-field magnetic circular dichroism (MCD) data. The PSO algorithm is used to determine the ground state of two catalytic intermediates from a flavodiiron protein with nitric oxide reductase activity. The fits of the spin Hamiltonians provide important geometric and electronic insight into these species.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Wei-Yao Hu, Kelin Li, Andrew Weitz, Aiwen Wen, Hyomin Kim, Jessica C. Murray, Ronghai Cheng, Baixiong Chen, Nathchar Naowarojna, Mark W. Grinstaff, Sean J. Elliott, Jie-Sheng Chen, Pinghua Liu
Summary: Rieske-type non-heme iron oxygenases/oxidases have wide applications in catalyzing various transformations, but are hindered by the requirement of expensive NAD(P)H and a proper reductase. This study demonstrates the use of Stc2 photocatalysis with eosin Y/sulfite as a photosensitizer/sacrificial reagent pair, bypassing the need for both reductase and NAD(P)H. The results show superior performance of Stc2 photo-biocatalysis compared to the Stc2-NAD(P)H-reductase system, suggesting the potential applicability of this photo-reduction system to other redox enzymes.
Article
Chemistry, Multidisciplinary
Jared C. Paris, Sha Hu, Aiwen Wen, Andrew C. Weitz, Ronghai Cheng, Leland B. Gee, Yijie Tang, Hyomin Kim, Arturo Vegas, Wei-chen Chang, Sean J. Elliott, Pinghua Liu, Yisong Guo
Summary: This study reports the first observation of a spin iron(IV) species in non-heme iron enzymes, which enables the formation of C-S bond catalyzed by OvoA in Methyloversatilis thermotolerans. This finding paves the way for understanding the mechanism of enzymatic oxidative C-S bond formation in the OSHA biosynthesis pathway.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chenjie Zeng, Andrew C. Weitz, Gayathri Withers, Tatsuya Higaki, Shuo Zhao, Yuxiang Chen, Roberto R. Gil, Michael P. Hendrich, Rongchao Jin