Article
Chemistry, Multidisciplinary
Hyunuk Eom, Yuanxin Cao, Hyunsoo Kim, Sam P. de Visser, Woon Ju Song
Summary: The catalytic activity of metalloenzymes is strongly related to the metal elements in the active sites. Nonheme quercetin dioxygenases (QueD) are known to have different first-row transition-metal ions binding in their active sites, but the enzyme becomes inactive when the metal is substituted. In this study, manganese-dependent QueD was converted into a nickel-dependent enzyme through directed evolution. The acquired mutations primarily rearrange hydrophobic residues in the active site pocket, adjusting the electronic structure of the enzyme-substrate complex to compensate for the effects of metal substitution.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Sayontani Sinha Roy, Kallol Talukdar, Jonah W. Jurss
Summary: A series of molecular Mn catalysts with aniline groups were developed for electrochemical and photochemical CO2 reduction, with catalyst 1-Mn showing the highest efficiency. The proximity of the aniline groups to the active site is crucial in determining catalytic performance, with high faradaic efficiencies achieved using trifluoroethanol as a proton source and a shift in product selectivity observed under photocatalytic conditions.
Article
Parasitology
Jessica Hickson, Lucas Felipe Almeida Athayde, Thaina Godinho Miranda, Policarpo Ademar Sales Junior, Anderson Coqueiro Dos Santos, Lucia Maria da Cunha Galvao, Antonia Claudia Jacome da Camara, Daniella Castanheira Bartholomeu, Rita de Cassia Moreira de Souza, Silvane Maria Fonseca Murta, Laila Alves Nahum
Summary: This study investigates the genes coding for iron superoxide dismutase (FeSOD) in T. cruzi strains from an evolutionary perspective. The results reveal the molecular biodiversity of T. cruzi FeSODs and identify potential drug targets.
PARASITES & VECTORS
(2022)
Article
Multidisciplinary Sciences
Dongdong Wang, Jiawei Liu, Changlai Wang, Weiyun Zhang, Guangbao Yang, Yun Chen, Xiaodong Zhang, Yinglong Wu, Long Gu, Hongzhong Chen, Wei Yuan, Xiaokai Chen, Guofeng Liu, Bin Gao, Qianwang Chen, Yanli Zhao
Summary: Cancer immunotherapy is revolutionizing oncology and the combination of nanotechnology and immunotherapy provides an opportunity to enhance antitumor immune response. This study presents a mitochondria-targeting nanoplatform, MiBaMc, which consists of Prussian blue nanoparticles derived from bacteria and shows enhanced tumor inhibition in mouse models. The findings demonstrate the potential of targeted nanoparticles in boosting antitumor immunity.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Mina R. Narouz, Patricia De La Torre, Lun An, Christopher J. Chang
Summary: By decorating iron porphyrins with imidazolium pendants, a family of multifunctional secondary coordination sphere groups is developed to enhance catalytic performance in synthetic systems. In the electrochemical CO2 reduction reaction (CO2RR), these imidazolium units promote multiple synergistic effects to increase CO2RR activity. The study also reveals that through-space charge effects have a stronger impact on catalytic CO2RR performance than hydrogen bonding in this context.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Brena L. Thompson, Zachariah M. Heiden
Summary: Electron transfer promoted by the coordination of a substrate molecule to a Lewis acid or hydrogen bonding group is a critical step in many biological and catalytic transformations. This computational study investigates the nature of the interaction between benzoquinone and one and two Lewis acids by examining the influence of Lewis acid strength on the ability to alter the two reduction potentials of the coordinated benzoquinone molecule. Coordination of benzoquinone to a Lewis acid became more favorable by 25 kcal mol(-1) with each reduction of the benzoquinone fragment. Coordination of benzoquinone to a Lewis acid also shifted each of the reduction potentials of the coordinated benzoquinone anodically by 0.50 to 1.5 V, depending on the strength of the Lewis acid, with stronger Lewis acids exhibiting a larger effect on the reduction potential. Coordination of a second Lewis acid further altered each of the reduction potentials by an additional 0.70 to 1.6 V. Replacing one of the Lewis acids with a proton resulted in the ability to modify the pK(a) of the protonated Lewis acid-Q/[Q](-)/[Q](2-) adducts by about 10 pK(a) units, in addition to being able to alter the ability to transfer a hydrogen atom by 10 kcal mol(-1), and the capacity to transfer a hydride by about 30 kcal mol(-1).
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
John C. Dickenson, MacKenzie E. Haley, Jacob T. Hyde, Zachary M. Reid, Travis J. Tarring, Diana A. Iovan, Daniel P. Harrison
Summary: The research shows a strong correlation between the redox potentials of metal- and ligand-centered events with the Hammett parameters of aryl substituents. The introduction of a phenyl spacer results in a significant decrease in electron density, affecting the redox properties of homoleptic transition-metal complexes.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yida Zhang, Qingyu Wang, Shaokang Yang, Hengwei Wang, Dewei Rao, Tao Chen, Gongming Wang, Junling Lu, Junfa Zhu, Shiqiang Wei, Xusheng Zheng, Jie Zeng
Summary: This study demonstrates that the strong interaction between Ru single atoms and the second coordination sphere can enrich photogenerated electrons at Ru active sites and enhance N-2 photofixation activity. Mechanistic studies reveal that Ru-Co coordination serves as an additional photoelectron transfer channel, facilitating the photoreduction of N-2 into NH3.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Alexandra N. Downing, Michael K. Coggins, Penny Chaau Yan Poon, Julie A. Kovacs
Summary: The work highlights the precise control of reactivity by the inner coordination sphere of metalloenzymes and transition-metal complexes. By studying a crystallographically characterized Mn-peroxo complex, the researchers demonstrate the stability differences and electronic structure insights between alkoxide-ligated and thiolate-ligated derivatives. This research sheds light on the factors influencing the stability of metal complexes and provides a rationale for ligand selection in oxygen-evolving systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Jiahui Ji, Qingyun Yan, Pengcheng Yin, Shinya Mine, Masaya Matsuoka, Mingyang Xing
Summary: A CoS2-x mixed with Fe2+ system was developed for the sustained release of singlet oxygen (O-1(2)) through ultrasonic treatment, effectively degrading various organic pollutants. This system can efficiently degrade organic pollutants for up to 30 days, surpassing the current CuPx system by a significant margin.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Anthony R. Ramuglia, Vishal Budhija, Khoa H. Ly, Michael Marquardt, Matthias Schwalbe, Inez M. Weidinger
Summary: The newly synthesized iron porphyrin complex Py2XPFe contains a bispyridylamine-based hanging unit, which serves as a hydrogen bonding site to facilitate proton transfer and increase the rate of catalysis in electrocatalytic CO2 reduction reactions. The hanging group beneficially impacts the rate of catalysis when compared to the non-functionalized analog TMPFe, and the addition of weak Bronsted acids further enhances the catalytic activity of Py2XPFe.
Article
Geosciences, Multidisciplinary
Leslie J. Robbins, Mojtaba Fakhraee, Albertus J. B. Smith, Brendan A. Bishop, Elizabeth D. Swanner, Caroline L. Peacock, Chang -Le Wang, Noah J. Planavsky, Christopher T. Reinhard, Sean A. Crowe, Timothy W. Lyons
Summary: Oxygenic photosynthesis is crucial for the existence of complex life on Earth, but determining its emergence has been challenging. Sedimentary manganese enrichments have been considered as evidence, but their relation to oxygenation has been debated. This review argues that the presence of shallow oxygenated seawater is necessary for significant sedimentary Mn enrichments, and suggests that oxygenic photosynthesis emerged hundreds of millions of years before irreversible atmospheric oxygenation.
EARTH-SCIENCE REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Xu Gao, Liang Fang, HaoJi Wang, Suwon Lee, Huanqing Liu, Shu Zhang, Jinqiang Gao, Yu Mei, Mihui Park, Jing Zhang, Mingzhe Chen, Limin Zhou, Wentao Deng, Guoqiang Zou, Hongshuai Hou, Yong-Mook Kang, Xiaobo Ji
Summary: Fe-Mn based layered oxides are potential cathode materials for SIBs with high capacities and abundant ingredients. The capacity fading mechanism of these oxides is comprehensively investigated, revealing the role of Fe migration and structural distortion. The O3-P3 phase transition is constrained along with Fe migration, leading to intensified polarization and capacity loss. The capacity fading within the desodiation depth is dominantly rooted in Fe4+ activation and Mn-dissolution aggravated passivation. These findings provide insights for designing desirable cathodes for SIBs.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Geology
Zhiyong Lin, Xiaoming Sun, Andrew P. Roberts, Harald Strauss, Yang Lu, Xin Yang, Junli Gong, Guanhua Li, Benjamin Brunner, Jorn Peckmann
Summary: The study reports a novel authigenic nanoscale magnetite source in marine methane seep sediments, with characteristics of larger particles and distinctive structures, mainly as a byproduct of microbial iron reduction within methanic sediments with rapidly changing redox conditions. This magnetite may have formed due to alterations in redox conditions within methane sediments.
Article
Engineering, Chemical
Junying Wan, Tiejun Chen, Xianlin Zhou, Yanhong Luo, Wei Liu, Qicai Lu
Summary: The study found that the addition of high-manganese iron ore can promote the direct reduction process of high-iron red mud and increase the metallization rate.
MINERALS ENGINEERING
(2021)