N-heterocyclic carbene (NHC) ligands have had a major impact in homogeneous catalysis, however, their potential role in biological systems is essentially unexplored. We replaced a copper-coordinating histidine (His) in the active site of the redox enzyme azurin with exogenous dimethyl imidazolylidene. This NHC rapidly restores the type-1 Cu center, with spectroscopic properties (EPR, UV/Vis) that are identical to those from N-coordination of the His in the wild type. However, the introduction of the NHC markedly alters the redox potential of the metal, which is a key functionality of this blue copper protein. These results suggest that C-bonding for histidine is plausible and a potentially relevant bonding mode of redox-active metalloenzymes in their (transient) active states.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201807168 | DOI Listing |
Inorg Chem
January 2025
State Key Laboratory of Molecular & Process Engineering, SINOPEC Research Institute of Petroleum Processing, Beijing 100083, China.
The ZSM-5 zeolite is the key active component in high-severity fluid catalytic cracking (FCC) catalysts and is routinely activated by phosphorus compounds in industrial production. To date, however, the detailed structure and function of the introduced phosphorus still remain ambiguous, which hampers the rational design of highly efficient catalysts. In this work, using advanced solid-state NMR techniques, we have quantitatively identified a total of seven types of P-containing complexes in P-modified ZSM-5 zeolite and clearly revealed their structure, location, and catalytic role.
View Article and Find Full Text PDFActa Pharm Sin B
December 2024
State Key Laboratory of Cellular Stress Biology and Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Science, Xiamen University, Xiamen 361102, China.
The orphan nuclear receptor Nur77 is emerging as an attractive target for cancer therapy, and activating Nur77's non-genotypic anticancer function has demonstrated strong therapeutic potential. However, few Nur77 site B ligands have been identified as excellent anticancer compounds. There are no co-crystal structures of effective anticancer agents at Nur77 site B, which greatly limits the development of novel Nur77 site B ligands.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Hunan University, Chemistry and Chemical Engineering, Lushan South Road, Yuelu District, 410082, Changsha, CHINA.
Site density and turnover frequency are the two fundamental kinetic descriptors that determine the oxygen reduction activity of iron-nitrogen-carbon (Fe-N-C) catalysts. However, it remains a grand challenge to simultaneously optimize these two parameters in a single Fe-N-C catalyst. Here we show that treating a typical Fe-N-C catalyst with ammonium iodine (NH4I) vapor via a one-step chemical vapor deposition process not only increases the surface area and porosity of the catalyst (and thus enhanced exposure of active sites) via the etching effect of the in-situ released NH3, but also regulates the electronic structure of the Fe-N4 moieties by the iodine dopants incorporated into the carbon matrix.
View Article and Find Full Text PDFSmall
January 2025
Institute of Nano Science and Technology, Sector-81, Knowledge city, S.A.S. Nagar, Punjab, 140306, India.
Oxygen electrocatalysis plays a pivotal role in energy conversion and storage technologies. The precise identification of active sites for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for developing an efficient bifunctional electrocatalyst. However, this remains a challenging endeavor.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, The University of Hong Kong, Hong Kong Island 000000, Hong Kong SAR, China.
Methanol (ME) is a liquid hydrogen carrier, ideal for on-site-on-demand H generation, avoiding its costly and risky distribution issues, but this "ME-to-H" electric conversion suffers from high voltage (energy consumption) and competitive oxygen evolution reaction. Herein, we demonstrate that a synergistic cofunctional PtPd/(Ni,Co)(OH) catalyst with Pt single atoms (Pt) and Pd nanoclusters (Pd) anchored on OH-vacancy(V)-rich (Ni,Co)(OH) nanoparticles create synergistic triadic active sites, allowing for methanol-enhanced low-voltage H generation. For MOR, OH* is preferentially adsorbed on Pd and then interacts with the intermediates (such as *CHO or *CHOOH) adsorbed favorably on neighboring Pt with the assistance of hydrogen bonding from the surface hydrogen of (Ni,Co)(OH).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!