We have designed a nanosensor to study the potential function of metallothionein (MT) in metal transfer and its interactions with redox partners and ligands by attaching two fluorescent probes to recombinant human MT. The specific labeling takes advantage of two different modification reactions. One is based on the fact that recombinant MT has a free N-terminal amino group when produced by the IMPACT T7 expression and purification system, the other on the observation that one human MT isoform (1b) contains an additional cysteine at position 32. It is located in the linker region of the molecule, allowing the introduction of a probe between the two domains. An S32C mutation was introduced into hMT-2. Its thiol reactivity, metal binding capacity, and CD and UV spectra all demonstrate that the additional cysteine contains a free thiol(ate); it perturbs neither the overall structure of the protein nor the formation of the metalthiolate clusters. MT containing only cadmium was labeled stoichiometrically with Alexa 488 succinimidyl ester at the N terminus and with Alexa 546 maleimide at the free thiol group, followed by conversion to MT containing only zinc. Energy transfer between Alexa 488 (donor) and Alexa 546 (acceptor) in double-labeled MT allows the monitoring of metal binding and conformational changes in the N-terminal beta-domain of the protein.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC151327 | PMC |
http://dx.doi.org/10.1073/pnas.0438005100 | DOI Listing |
Chem Sci
January 2025
School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Chemical Theory and Mechanism, Chongqing University Chongqing 401331 China
Atomically precise gold nanoclusters have shown great promise as model electrocatalysts in pivotal electrocatalytic processes such as the hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CORR). Although the influence of ligands on the electronic properties of these nanoclusters is well acknowledged, the ligand effects on their electrocatalytic performances have been rarely explored. Herein, using [Au(SR)] nanoclusters as a prototype model, we demonstrated the importance of ligand hydrophilicity hydrophobicity in modulating the interface dynamics and electrocatalytic performance.
View Article and Find Full Text PDFChem Sci
January 2025
State Key Laboratory of Powder Metallurgy, Central South University Changsha 410083 P. R. China
In overcoming the barrier of rapid Li transfer in lithium-ion batteries at extreme temperatures, the desolvation process and interfacial charge transport play critical roles. However, tuning the solvation structure and designing a kinetically stable electrode-electrolyte interface to achieve high-rate charging and discharging remain a challenge. Here, a lithium nonafluoro-1-butanesulfonate (NFSALi) additive is introduced to optimize stability and the robust solid electrolyte interface film (SEI), realizing a rapid Li transfer process and the structural integrity of electrode materials.
View Article and Find Full Text PDFACS Phys Chem Au
January 2025
University of Duisburg-Essen, Faculty of Chemistry, Theoretical Catalysis and Electrochemistry, Universitätsstraße 5, Essen 45141, Germany.
The direct conversion of dinitrogen to nitrate is a dream reaction to combine the Haber-Bosch and Ostwald processes as well as steam reforming using electrochemistry in a single process. Regrettably, the corresponding nitrogen oxidation (NOR) reaction is hampered by a selectivity problem, since the oxygen evolution reaction (OER) is both thermodynamically and kinetically favored in the same potential range. This opens the search for the identification of active and selective NOR catalysts to enable nitrate production under anodic reaction conditions.
View Article and Find Full Text PDFACS Cent Sci
January 2025
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Multicomponent reactions (MCRs), highly sought-after methods to produce atom-, step-, and energy-economic organic syntheses, have been developed extensively. However, catalytic asymmetric MCRs, especially those involving radical species, remain largely unexplored owing to the difficulty in stereoselectively regulating the extraordinarily high reactivity of open-shell radical species. Herein, we report a conceptually novel catalytic asymmetric three-component radical cascade reaction of readily accessible glycine esters, α-bromo carbonyl compounds and 2-vinylcyclopropyl ketones via synergistic photoredox/Brønsted acid catalysis, in which three sequential C-C (σ/π/σ) bond-forming events occurred through a radical addition/ring-opening/radical-radical coupling protocol, affording an array of valuable enantioenriched unnatural α-amino acid derivatives bearing two contiguous stereogenic centers and an alkene moiety in moderate to good yield with high diastereoselectivity, excellent enantioselectivity and good -dominated geometry under mild reaction conditions.
View Article and Find Full Text PDFACS Omega
January 2025
Key Laboratory of High Performance Ship Technology, Wuhan University of Technology, Ministry of Education, Wuhan 430063, China.
Wearable thermoelectric generator (TEG) can collect human body heat and convert it into electrical energy, achieving self-powering of the device and thus becoming a hot research topic at present. By utilization of three-dimensional spiral thin-film thermoelectric structures and passive radiation cooling methods, the heat transfer area can be increased and power generation can be enhanced. In order to study the effect of outdoor radiation cooling on the thermoelectric performance of spiral heating, as well as the TEG performance output under different external environments and circuit loads, this paper proposes a new three-dimensional coupled numerical model of the spiral thermoelectric wristband system with multiple physical fields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!