ADVANCED MATERIALS
·
2022
·Vol. 35
·期 3
·2208121
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IF 32.086
Tong Wu,Kang Liu,Shuhai Liu,Xiaolong Feng,Xuefeng Wang,Longfei Wang,Yong Qin,Zhong Lin Wang
Catalysis is vitally important for chemical engineering, energy, and environment. It is critical to discover new mechanisms for efficient catalysis. For piezoelectric/pyroelectric/ferroelectric materials that have a non-centrosymmetric structure, interfacial polarization-induced redox reactions at surfaces leads to advanced mechanocatalysis. Here, the first flexocatalysis for 2D centrosymmetric semiconductors, such as MnO 2 nanosheets, is demonstrated largely expanding the polarization-based-mechanocatalysis to 2D centrosymmetric materials. Under ultrasonic excitation, the reactive species are created due to the strain-gradient-induced flexoelectric polarization in MnO 2 nanosheets composed nanoflowers. The organic pollutants (Methylene Blue et al.) can be effectively degraded within 5 min; the performance of the flexocatalysis is comparable to that of state-of-the-art piezocatalysis, with excellent stability and reproducibility. Moreover, the factors related to flexocatalysis such as material morphology, adsorption, mechanical vibration intensity, and temperature are explored, which give deep insights into the mechanocatalysis. This study opens the field of flexoelectric effect-based mechanochemistry in 2D centrosymmetric semiconductors.
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2024
·
IF 13
Anshuo Li,Liuyang Xu,Yanmin Jia,Meng Yuan,Jinhui Zhang,Hengrui Liu,Shiqi Liu,Yuhui Zhu,Xindi Wei,Wenkang Tu,Yuchu He,Song Ni,Xinquan Jiang,Xuwu Zhang
Photodynamic therapy (PDT) is long-standing suffered from elevated tumor interstitial fluid pressure (TIFP) and prevalent hypoxic microenvironment within the solid malignancies. Herein, sound-activated flexocatalysis is developed to overcome the dilemma of PDT through both enhancing tumor penetration of photosensitizers by reducing TIFP and establishing an oxygen-rich microenvironment. In detail, a Schottky junction is constructed by flexocatalyst MoSe 2 nanoflowers and Pt. Subsequently, the Schottky junction is loaded with the photosensitizer indocyanine green (ICG) and encapsulated within tumor cytomembrane to constitute a bionic-flexocatalytic nanomedicine (MPI@M). After targeting the tumor, MPI@M orchestrates flexocatalytic water splitting in tumor interstitial fluid under acoustic stimulation to lower TIFP, which boosted the tumor penetration of ICG. Concurrently, the oxygen released from the flexocatalytic water splitting overcomes the limitation of hypoxia against PDT. Furthermore, superfluous singlet oxygen generated by PDT can induce mitochondrial dysfunction for further tumor cell apoptosis. After 60 min of flexocatalysis, both the 30% decrease of TIFP and the relieved tumor hypoxia are observed, significantly promoting the therapeutic effect of PDT. Consequently, MoSe 2 /Pt junction nanoflowers, with the excellent flexocatalytic performance, hold significant potential for future applications in biocatalytic cancer therapies.
研究领域:
肿瘤学
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生物医学工程
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纳米医学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOLOGICAL CHEMISTRY
·
2021
·Vol. 297
·期 1
·
IF 5.157
Yi Zhang,Hai-Tao Ding,Wen-Xin Jiang,Xia Zhang,Hai-Yan Cao,Jing-Ping Wang,Chun-Yang Li,Feng Huang,Xi-Ying Zhang,Xiu-Lan Chen,Yu-Zhong Zhang,Ping-Yi Li
SGNH-type acetyl xylan esterases (AcXEs) play important roles in marine and terrestrial xylan degradation, which are necessary for removing acetyl side groups from xylan. However, only a few cold-adapted AcXEs have been reported, and the underlying mechanisms for their cold adaptation are still unknown because of the lack of structural information. Here, a cold-adapted AcXE, AlAXEase, from the Arctic marine bacterium Arcticibacterium luteifluviistationis SM1504T was characterized. AlAXEase could deacetylate xylooligosaccharides and xylan, which, together with its homologs, indicates a novel SGNH-type carbohydrate esterase family. AlAXEase showed the highest activity at 30 °C and retained over 70% activity at 0 °C but had unusual thermostability with a Tm value of 56 °C. To explain the cold adaption mechanism of AlAXEase, we next solved its crystal structure. AlAXEase has similar noncovalent stabilizing interactions to its mesophilic counterpart at the monomer level and forms stable tetramers in solutions, which may explain its high thermostability. However, a long loop containing the catalytic residues Asp200 and His203 in AlAXEase was found to be flexible because of the reduced stabilizing hydrophobic interactions and increased destabilizing asparagine and lysine residues, leading to a highly flexible active site. Structural and enzyme kinetic analyses combined with molecular dynamics simulations at different temperatures revealed that the flexible catalytic loop contributes to the cold adaptation of AlAXEase by modulating the distance between the catalytic His203 in this loop and the nucleophilic Ser32. This study reveals a new cold adaption strategy adopted by the thermostable AlAXEase, shedding light on the cold adaption mechanisms of AcXEs.
研究领域:
生物化学
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结构生物学
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酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）