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921.
Yajie Liu Zelin Duan Jing Fang Fan Zhang Prof. Junyu Xiao Prof. Wen-Bin Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16256-16261
Herein, we report the biosynthesis of protein heterocatenanes using a programmed sequence of multiple post-translational processing events including intramolecular chain entanglement, in situ backbone cleavage, and spontaneous cyclization. The approach is general, autonomous, and can obviate the need for any additional enzymes. The catenane topology was convincingly proven using a combination of SDS-PAGE, LC-MS, size exclusion chromatography, controlled proteolytic digestion, and protein crystallography. The X-ray crystal structure clearly shows two mechanically interlocked protein rings with intact folded domains. It opens new avenues in the nascent field of protein-topology engineering. 相似文献
922.
Guangjun Li Weigang Hu Yongnan Sun Jiayu Xu Xiao Cai Xinglian Cheng Yuying Zhang Ancheng Tang Xu Liu Prof. Mingyang Chen Prof. Weiping Ding Prof. Yan Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21321-21328
The emergence of atomically precise metal nanoclusters with unique electronic structures provides access to currently inaccessible catalytic challenges at the single-electron level. We investigate the catalytic behavior of gold Au25(SR)18 nanoclusters by monitoring an incoming and outgoing free valence electron of Au 6s1. Distinct performances are revealed: Au25(SR)18− is generated upon donation of an electron to neutral Au25(SR)180 and this is associated with a loss in reactivity, whereas Au25(SR)18+ is generated from dislodgment of an electron from neutral Au25(SR)180 with a loss in stability. The reactivity diversity of the three Au25(SR)18 clusters stems from different affinities with reactants and the extent of intramolecular charge migration during the reactions, which are closely associated with the valence occupancies of the clusters varied by one electron. The stability difference in the three clusters is attributed to their different equilibria, which are established between the AuSR dissociation and polymerization influenced by one electron. 相似文献
923.
Dr. Xiaocui Guo Prof. Feng Li Chunxia Liu Yi Zhu Nannan Xiao Dr. Zi Gu Prof. Dan Luo Prof. Jianhui Jiang Prof. Dayong Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20832-20839
The design of controllable dynamic systems is vital for the construction of organelle-like architectures in living cells, but has proven difficult due to the lack of control over defined topological transformation of self-assembled structures. Herein, we report a DNA based dynamic assembly system that achieves lysosomal acidic microenvironment specifically inducing topological transformation from nanoparticles to organelle-like hydrogel architecture in living cells. Designer DNA nanoparticles are constructed from double-stranded DNA with cytosine-rich stick ends (C-monomer) and are internalized into cells through lysosomal pathway. The lysosomal acidic microenvironment can activate the assembly of DNA monomers, inducing transformation from nanoparticles to micro-sized organelle-like hydrogel which could further escape into cytoplasm. We show how the hydrogel regulates cellular behaviors: cytoskeleton is deformed, cell tentacles are significantly shortened, and cell migration is promoted. 相似文献
924.
Peijun Wang Bolun Wang Yucheng Liu Dr. Lin Li Hua Zhao Prof. Yonghua Chen Prof. Jiyang Li Prof. Shengzhong Liu Prof. Kui Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23300-23306
Metal halide perovskites have been widely applied in optoelectronic fields, but their poor stability hinders their actual applications. A perovskite–zeolite composite was synthesized via in situ growth in air from aluminophosphate AlPO-5 zeolite crystals and perovskite nanocrystals. The zeolite matrix provides quantum confinement for perovskite nanocrystals, achieving efficient green emission, and it passivates the defects of perovskite by H-bonding interaction, which leads to a longer lifetime compared to bulk perovskite film. Furthermore, the AlPO-5 zeolite also acts as a protection shield and enables ultrahigh stability of perovskite nanocrystals under 150 °C heat stress, under a 15-month long-term ambient exposure, and even in water for more than 2 weeks, respectively. The strategy of in situ passivation and encapsulation for the perovskite@AlPO-5 composite was amenable to a range of perovskites, from MA- to Cs-based perovskites. Benefiting from high stability and photoluminescence performance, the composite exhibits great potential to be virtually applied in light-emitting diodes (LEDs) and backlight displays. 相似文献
925.
Guifa Zhai Wenyan Wang Dr. Wei Xu Guo Sun Chaoqun Hu Xiangming Wu Zisong Cong Liang Deng Yanrong Shi Prof. Dr. Peter F. Leadlay Prof. Dr. Heng Song Prof. Dr. Kui Hong Prof. Dr. Zixin Deng Prof. Dr. Yuhui Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22926-22930
The colinearity of canonical modular polyketide synthases, which creates a direct link between multienzyme structure and the chemical structure of the biosynthetic end-product, has become a cornerstone of knowledge-based genome mining. Herein, we report genetic and enzymatic evidence for the remarkable role of an enoylreductase in the polyketide synthase for azalomycin F biosynthesis. This internal enoylreductase domain, previously identified as acting only in the second of two chain extension cycles on an initial iterative module, is shown to also catalyze enoylreduction in trans within the next module. The mechanism for this rare deviation from colinearity appears to involve direct cross-modular interaction of the reductase with the longer acyl chain, rather than back transfer of the substrate into the iterative module, suggesting an additional and surprising plasticity in natural PKS assembly-line catalysis. 相似文献
926.
Dr. Yao Xiao Yan-Fang Zhu Dr. Wei Xiang Dr. Zhen-Guo Wu Yong-Chun Li Jing Lai Shi Li Dr. Enhui Wang Zu-Guang Yang Chun-Liu Xu Prof. Ben-He Zhong Prof. Xiao-Dong Guo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(4):1507-1511
Demands for large-scale energy storage systems have driven the development of layered transition-metal oxide cathodes for room-temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal layered-tunnel heterostructure Na0.44Co0.1Mn0.9O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered-tunnel electrode shows outstanding electrochemical performance in sodium half-cell system and excellent compatibility with hard carbon anode in sodium full-cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium-ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high-energy X-ray diffraction and ex situ X-ray absorption spectroscopy as well as operando X-ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs. 相似文献
927.
Two new 1D helical coordination polymers based on polyoxometalate were synthesized by self-assembly of Keggin-type POMs and copper salts in the presence of triangular N-heterocyclic derivatives or long-chain N-containing carboxylate ligand, that are, (H3O)[{Cu(H2tpim)2}{SiMo12O40}] · 0.5H2O [Htpim = 2,4,5-tri(4-pyridyl)-imidazole] ( 1 ) and [Cu2(Hcpp)3(cpp)(H2O)][PMo12O40] · 2H2O [Hcpp = 1-(4-cyanobenzyl)-3–2-yl)pyrazole] ( 2 ). Their structures were determined by single-crystal X-ray diffraction and further characterized by elemental analyses and TG analyses. Compounds 1 and 2 exhibit (1D→2D) interdigitated architectures assembled from 1D helical chains. In compound 1 , the achiral 2D interdigitated nets containing left- and right-handed helixes are further interdigitated with each other to form a 3D supramolecular framework. In compound 2 , adjacent 2D interdigitated layers with opposite chirality are further extended by supramolecular interactions into a 3D supramolecular network, in which non-coordinating Keggin-type POMs as guests are encapsulated. 相似文献
928.
Integration of MnOx into the carbon matrix proves a viable strategy to improve the electrochemical performance of MnOx materials. Mn3O4 nanoparticle-decorated N-doped carbon composites (Mn3O4@N-doped carbon) were facilely prepared from a non-porous eight-fold interpenetrated ZnII-based MOF, which involves first synthesis of bimetallic Mn/Zn-MOF in one-pot reaction followed by direct pyrolysis at 1000 °C. In 0.1 m KOH solution, the optimal Mn3O4@N-doped carbon exhibits decent oxygen reduction activity with the onset potential (Eonset) of 0.94 V (vs. RHE) and half-wave potential (E1/2) of 0.81 V (vs. RHE), excellent methanol tolerance as well as good durability. 相似文献
929.
Dr. Xi-Sha Zhang Yan-Ying Huang Jing Zhang Dr. Wei Meng Dr. Qian Peng Ruirui Kong Zhenwei Xiao Dr. Jie Liu Miaofei Huang Dr. Yuanping Yi Liangliang Chen Qingrui Fan Dr. Gaobo Lin Dr. Zitong Liu Dr. Guanxin Zhang Dr. Lang Jiang Prof. Dr. Deqing Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3557-3561
Polycyclic aromatic hydrocarbons with hexagons/pentagons or hexagons/heptagons have been intensively investigated in recent years, but those with simultaneous presence of hexagons, pentagons and heptagons remain rare. In this paper, we report dicyclohepta[ijkl,uvwx]rubicene ( DHR ), a non-benzenoid isomer of dibenzo[bc,kl]coronene with two pentagons and two heptagons. We developed an efficient and scalable synthetic method for DHR by using Scholl reaction and dehydrogenation. Crystal structure of DHR shows that the benzenoid rings, two pentagons and two heptagons are coplanar. The bond lengths analysis and the ICSS(1)zz and LOL-π calculations indicate that the incorporation of two formal azulene moieties has an effect on the conjugated structure. The π-electrons of benzenoid and pentagon rings are more delocalized. Cyclic voltammetry studies indicate that DHR shows multiple oxidation and reduction potentials. Interestingly, DHR exhibits unusual S0 to S2 absorption and abnormal anti-Kasha S2 to S0 emission. Moreover, crystals of DHR exhibit semiconducting behaviour with hole mobility up to 0.082 cm2 V−1 s−1. 相似文献
930.
Shan Jin Manman Zhou Xi Kang Xiaowu Li Wenjun Du Xiao Wei Shuang Chen Dr. Shuxin Wang Prof. Manzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):3919-3923
The high-dimensional (that is, three-dimensional (3D)) assembly of nanomaterials is an effective means of improving their properties; however, achieving this assembly at the atomic level remains challenging. Herein, we obtained a novel nanocluster, [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl (Dppp=1,3-bis(diphenylphosphino)propane) showing a 3D octameric assembly mode involving the kernel penetration of eight complete icosahedral Au@Ag10Au2 units for the first time. The atomically precise structure was determined by single-crystal X-ray diffraction, and further confirmed by thermogravimetric analysis, X-ray photoelectron spectroscopy, and electrospray ionization mass spectrometry measurements. Furthermore, ligand-induced transformation prompted the conversion of [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl, with complete octameric fusion into [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2, with incomplete octameric fusion. These observations will hopefully facilitate further research on the assembly of M13 nanobuilding blocks. 相似文献