排序方式: 共有48条查询结果,搜索用时 171 毫秒
41.
Yanzhen Yin Chao Lang Xiaoxi Hu Zhongfeng Shi Yun Wang Shufei Jiao Chengxiang Cai Junqiu Liu 《Russian Journal of Bioorganic Chemistry》2014,40(2):162-169
A novel guest biomimetic glutathione peroxidase(3,3′-tellurobis(propane-3,1-diyl) diadamantanecarboxylate, denoted as ADA-Te-ADA) was synthesized. ADA-Te-ADA functioned to overcome the disadvantages in the construction of building block for giant supramolecular biomimetic enzyme. To reveal the catalytic property of hydrophobic ADA-Te-ADA, the catalytic mechanism was investigated using PBS (phosphate buffer (pH = 7.0, 50 mM))/methanol solvent mixture as assay solution. It indicated that ADA-Te-ADA exhibited typical enzyme catalytic behavior by saturation kinetics measurement. Importantly, ADA-Te-ADA exhibited the typical solvent-dependent catalytic behavior. And the highest catalytic rate 4.29 μM × min?1 was obtained when the volume ratio of PBS: methanol was 5: 5. Especially, the catalytic rates obtained based on various substrates proved that ADA-Te-ADA slightly displayed special substrate selectivity, which was the ideal catalytic characterization of building block for giant supramolecular biomimetic enzyme. The success-fully synthesis of ADA-Te-ADA might highlight for the understanding of the catalytic mechanism of hydrophobic guest biomimetic glutathione peroxidase. And it also might provide the basement for the construction of giant supramolecular biomimetic enzyme. 相似文献
42.
Junqiu Jiang Qingliang Zhao Jinna Zhang Guodong Zhang Duu-Jong Lee 《Bioresource technology》2009,100(23):5808-5812
A two-chambered microbial fuel cell (MFC) with potassium ferricyanide as its electron acceptor was utilized to degrade excess sewage sludge and to generate electricity. Stable electrical power was produced continuously during operation for 250 h. Total chemical oxygen demand (TCOD) of sludge was reduced by 46.4% when an initial TCOD was 10,850 mg/l. The MFC power output did not significantly depend on process parameters such as substrate concentration, cathode catholyte concentration, and anodic pH. However, the MFC produced power was in close correlation with the soluble chemical oxygen demand (SCOD) of sludge. Furthermore, ultrasonic pretreatment of sludge accelerated organic matter dissolution and, hence, TCOD removal rate in the MFC was increased, but power output was insignificantly enhanced. This study demonstrates that this MFC can generate electricity from sewage sludge over a wide range of process parameters. 相似文献
43.
Zhiming Zhang Qiuan Fu Xiangqiu Li Xin Huang Jiayun Xu Jiacong Shen Junqiu Liu 《Journal of biological inorganic chemistry》2009,14(5):653-662
Abstract Water-soluble Au nanocrystal (NC) micelles with an inserted catalytic Cu(II) center that act as excellent nanoenzyme models
for imitating ribonuclease were constructed by supramolecular self-assembly. The dodecane-1-thiol-based Au NC was constructed
first, and subsequently the cationic surfactant hexadecyltrimethylammonium bromide and the catalytic ligand (N
1,N
1-bis(2-aminoethyl)-N
2-dodecylethane-1,2-diamine) copper(II) were installed on the surface of the Au NC via hydrophobic interaction. The catalytic
capability of the Au NC micelles designed was estimated by the cleavage of a typical RNA analogue, 2-hydroxypropyl p-nitrophenyl phosphate (HPNP). The study of the catalytic behavior of Au NC micelle catalysis showed that the Au NC micelles
exhibited dramatic ribonuclease-like activity: a high rate acceleration of k
cat/k
uncat = 1.10 × 105 for the cleavage of HPNP in comparison with the spontaneous cleavage of HPNP (k
uncat) was observed. The catalytic capability for HPNP cleavage by these functionalized Au NC micelles can be compared with that
of covalent Au nanoparticles reported previously as nanozymes under comparable conditions. A detailed investigation of enzymatic
kinetics was carried out and a possible mechanism was suggested.
Graphical abstract
相似文献
44.
Xuanbo Song Ying Li Junqiu Liu Xiaohong Ji Lijun Zhao Yudan Wei 《Biological trace element research》2017,179(1):140-147
Cardiovascular disease and diabetes mellitus are prominent features of glucose and lipid metabolism disorders. Adiponectin is a key adipokine that is largely involved in glucose and lipid metabolism processes. A growing body of evidence suggests that chronic exposure to inorganic arsenic is associated with cardiovascular disease and diabetes mellitus. We hypothesized that arsenic exposure may increase the risk of cardiovascular disease and diabetes mellitus by affecting the level of adiponectin. In this study, we examined serum adiponectin levels, as well as serum levels of metabolic measures (including fasting blood glucose, insulin, total cholesterol, triglyceride, and high-density lipoprotein (HDL)-cholesterol) in C57BL/6 mice exposed to inorganic arsenic in drinking water (5 and 50 ppm NaAsO2) for 18 weeks. Body mass and adiposity were monitored throughout the study. We found no significant changes in serum insulin and glucose levels in mice treated with arsenic for 18 weeks. However, arsenic exposure decreased serum levels of adiponectin, triglyceride, and HDL-cholesterol. Further, an inverse relationship was observed between urinary concentrations of total arsenic and serum levels of adiponectin. This study suggests that arsenic exposure could disturb the metabolism of lipids and increase the risk of cardiovascular disease by reducing the level of adiponectin. 相似文献
45.
Li Lili Wang Kun Zhao Qingliang Gao Qingwei Zhou Huimin Jiang Junqiu Mei Wangyang 《Reviews in Environmental Science and Biotechnology》2022,21(3):665-689
Reviews in Environmental Science and Bio/Technology - Biogas from anaerobic digestion (AD), as an important alternative to fossil fuels, has contributed to energy recovery and environmental... 相似文献
46.
Chen Xuefei Huang Chao Li Kunlun Liu Junqiu Zheng Youyou Feng Yue Kai Guo-yin 《Phytochemistry Reviews》2023,22(1):169-186
Phytochemistry Reviews - β-Elemene is a valuable sesquiterpene isolated from the essential oil of the traditional Chinese medicine Curcuma wenyujin. As a Chinese class II non-cytotoxic... 相似文献
47.
Lei Ye Shu Shu Junqiu Jia Min Sun Siyi Xu Xinyu Bao Huijie Bian Yi Liu Meijuan Zhang Xiaolei Zhu Feng Bai Yun Xu 《Aging cell》2023,22(7):e13860
Pattern separation (PS) dysfunction is a type of cognitive impairment that presents early during the aging process, and this deficit has been attributed to structural and functional alterations in the dentate gyrus (DG) of the hippocampus. Absent in melanoma 2 (AIM2) is an essential component of the inflammasome. However, whether AIM2 plays a role in aging-associated cognitive dysfunction remains unclear. Here, we found that PS function was impaired in aging mice and was accompanied by marked synaptic loss and increased expression of AIM2 in the DG. Subsequently, we used an AIM2 overexpression virus and mice with AIM2 deletion to investigate the role of AIM2 in regulating PS function and synaptic plasticity and the mechanisms involved. Our study revealed that AIM2 regulates microglial activation during synaptic pruning in the DG region via the complement pathway, leading to impaired synaptic plasticity and PS function in aging mice. These results suggest a critical role for AIM2 in regulating synaptic plasticity and PS function and provide a new direction for ameliorating aging-associated cognitive dysfunction. 相似文献
48.
Xin Huang Yanzhen Yin Yang Liu Xiaolong Bai Zhiming Zhang Jiayun Xu Jiacong Shen Junqiu Liu 《Biosensors & bioelectronics》2009,25(3):657
Glutathione peroxidase (GPx, EC 1.11.1.9) is a key enzyme involved in scavenging of reactive oxygen species in biological system. For developing an efficient GPx-like antioxidant, catalytically necessary amino acid derivatives which located near the GPx active center were prepared as functional monomers. Via predetermined imprinting with substrate glutathione (GSH), a polymer-based GPx mimic with a similar structure of catalytic center of natural GPx was developed, and it demonstrated high-catalytic efficiency and substrate specificity. The imprinting polymer (I-PEM) exhibits GPx-like activity about three times higher than that of 2-SeCD, a cyclodextrin-based GPx mimic. The detailed studies on kinetics revealed that not only the substrate binding but also positional arrangement of reacting groups contribute significantly to the catalytic efficiency of the peroxidase model. 相似文献