APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2016
·Vol. 182
·期 3
·898-909
·
IF 1.606
Xu Jian-Miao,Cheng Feng,Fu Fang-Tian,Hu Hai-Feng,Zheng Yu-Guo
L -2-aminobutyric acid ( L -ABA) as a precursor for the anticonvulsant and the antituberculotic is a key intermediate in the chemical and pharmaceutical industries. Recently, leucine dehydrogenase (LeuDH) with NAD + regeneration was developed for L -ABA production on a large scale. Previously, the L -ABA yield was improved by optimizing conversion conditions, including cofactor regeneration and enzyme immobilization but not protein engineering on LeuDH due to lacking an applicable high-throughput screening (HTS) method. Recently, an HTS assay was developed by us, which enables researchers to engineer LeuDH in a relatively short period of time. Herein, a semirational engineering was performed on LeuDH to increase the catalytic efficiency of BcLeuDH. Firstly, the structure of wild-type (WT) BcLeuDH was modeled and seven potentially beneficial positions were selected for mutation. Five beneficial variants were then identified from the seven site-saturation mutagenesis (SSM) libraries by HTS and confirmed by rescreening via amino acid analyzer. The “best” variant M5 (WT + Q358N) showed 44.5-fold higher catalytic efficiency ( k
cat / K
M ) than BcLeuDH WT, which suggested that BcLeuDH M5 is an attractive candidate for L -ABA production on a large scale. Furthermore, the structure-functional relationship was investigated based on the docking and kinetic results.
研究领域:
生物技术
·
生物化工
·
酶学
·
药学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Ruijin Zeng,Minghao Qiu,Qing Wan,Zhisheng Huang,Xiaolong Liu,Dianping Tang,Dietmar Knopp
Large-scale, rapid, and inexpensive serological diagnoses of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) are of great interest in reducing virus transmission at the population level; however, their development is greatly plagued by the lack of available point-of-care methods, leading to low detection efficiency. Herein, an ultrasensitive smartphone-based electrochemical immunoassay is reported for rapid (less than 5 min), low-cost, easy-to-implement detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 N protein). Specifically, the electrochemical immunoassay was fabricated on a screen-printed carbon electrode coated with electrodeposited gold nanoparticles, followed by incubation of anti-N antibody (Ab) and bovine serum albumin as the working electrode. Accompanied by the antigen–antibody reaction between the SARS-CoV-2 N protein and the Ab, the electron transfer between the electroactive species [Fe(CN)6]3–/4– and the electrode surface is disturbed, resulting in reduced square-wave voltammetry currents at 0.075 V versus the Ag/AgCl reference electrode. The proposed immunoassay provided a good linear range with SARS-CoV-2 N protein concentrations within the scope of 0.01–1000 ng/mL (R2 = 0.9992) and the limit of detection down to 2.6 pg/mL. Moreover, the detection data are wirelessly transmitted to the interface of the smartphone, and the corresponding SARS-CoV-2 N protein concentration value is calculated and displayed. Therefore, the proposed portable detection mode offers great potential for self-differential diagnosis of residents, which will greatly facilitate the effective control and large-scale screening of virus transmission in resource-limited areas.
研究领域:
医学诊断
·
生物传感器
·
病毒学
✓ 已验证
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Yaohua Yang,Kai Yan,Jingdong Zhang
A Ni(OH) 2 /TiO 2 photoanode possessing high photoelectrocatalytic activity toward glucose oxidation driven by visible light was fabricated. The results indicated that deposition of Ni(OH) 2 on TiO 2 film electrode could remarkably promote the catalytic oxidation of glucose under visible light illumination. By applying a low voltage, the Ni(OH) 2 /TiO 2 electrode showed a linear photoelectrochemical response to glucose in the concentration range from 0.5 μM to 20 μM. Furthermore, the high photoelectrocatalytic activity of Ni(OH) 2 /TiO 2 electrode toward glucose oxidation was utilized to construct a glucose-air photofuel cell, which generated electrical signal responding to glucose concentration from 5 μM to 100 μM, without using external electrical power supply. Thus, dual non-enzymatic glucose sensors based on photocatalytic oxidation of glucose on the Ni(OH) 2 /TiO 2 electrode under visible light illumination were demonstrated.
研究领域:
生物医学工程
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2019
·
IF 3.218
Wei Chen,Jiayue Dong,Sihan Zhou,Chunyong Zhang,Degang Fu
1-naphthol (1-NAP) and 2-naphthol (2-NAP) are both hazardous pollutants which pose great threat to our living environment. In the current work, a comparative investigation on the electrochemical mineralization of 1-NAP and 2-NAP using boron-doped diamond (BDD) anode was presented. Experiments were carried out using synthetic 1-NAP or 2-NAP solutions containing Na 2 SO 4 as supporting electrolyte . A two-level factorial design methodology was adopted to optimize the mineralization process, six mathematical models were thus constructed and used to explore the structure-property relation involved. The results obtained suggested that 1-NAP was easier and faster to break down than 2-NPA under the same oxidation conditions, which were in line with the outcome obtained from cyclic voltammetry , HPLC and TOC measurements. To understand the destruction mechanism, the electron structures of 1-NAP and 2-NAP were further examined by the quantum chemistry calculations with density functional theory. It was also found that the results from frontier orbital analysis could well explain the differing mineralization performances recorded in BDD anode cell. Finally, with the aid of LC/MS analysis, the oxidation pathways of 1-NAP or 2-NAP on BDD anodes were proposed.
研究领域:
环境科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 2
·1046-1056
·
IF 3.094
Xiaohui Feng,Le Wang,Ran Wei,Ziyan Wang
Non-contact temperature sensors based on the fluorescence intensity ratio (FIR) have been widely investigated owing to their high sensitivity and reliable real-time monitoring. Herein, the SiO 2 -coated LiY(MoO 4 ) 2 @SiO 2 :Er 3+ ,Yb 3+ phosphor was investigated as an optical thermometry material, which was synthesized using the conventional solid state reaction and coated by a facile wet chemical route. The effect of surface modification on FIR was systematically characterized by structural analyses and spectral measurements and the temperature-dependent up-conversion FIR was investigated from 303 to 603 K under a 980 nm laser excitation. The results showed that the FIR value was thermally stable and the SiO 2 coating led to a higher FIR sensitivity as well as a higher saturation threshold. This work would pave a way to design interesting optical thermometry materials in up-conversion phosphors with better properties.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 49
·期 12
·3743-3749
·
IF 4.052
Ruling Tang,Chunli Hu,Jianghe Feng,Zhi Fang,Yan Chen,Fang Kong,Jianggao Mao
Two new inorganic metal borate derivatives, Sr5TeO2(BO3)4 and NaSr5(BO3)(SiO4)2, have been obtained through a high temperature solid reaction method. Sr5TeO2(BO3)4 crystallizes in a tetragonal space group of P4/mnc featuring a three-dimensional (3D) structure composed of a porous 3D strontium framework stabilized by the unique zero-dimensional (0D) [TeO2(BO3)4]10− anions. NaSr5(BO3)(SiO4)2 crystallizes in a monoclinic space group of P21/c with a 3D structure consisting of a splendid strontium 3D framework strengthened by isolated BO3 and SiO4 groups. The sodium cations located in the empty space of the structure. Thermal stability analyses, optical property measurements and theoretical studies of the compounds were performed. Refractive index calculations revealed that the birefringence of Sr5TeO2(BO3)4 and NaSr5(BO3)(SiO4)2 is 0.048 and 0.029, respectively, at 1064 nm.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
Chem Catalysis
·
2022
·
IF 0
Yu Li,Peiyuan Yao,Shiqing Zhang,Jinhui Feng,Hao Su,Xiangtao Liu,Xiang Sheng,Qiaqing Wu,Dunming Zhu,Yanhe Ma
Summary While formaldehyde is an emerging C1 resource for the synthesis of high value-added chemicals due to its high and versatile reactivity, selective activation and controllable transformation of formaldehyde still remains a great challenge. In particular, coupling of formaldehyde with small aldehydes such as 3-hydroxypropanal offers excellent opportunity for constructing valuable molecules but has not been realized. A benzaldehyde lyase from Herbiconiux sp. SALV-R1 was engineered through directed evolution to achieve the coupling of 3-hydroxypropanal and formaldehyde. A carbonyl reductase and a transaminase were identified to catalyze reduction or transamination of 1,4-dihydroxybutan-2-one, a highly functionalized small ketone. The newly attained enzymatic hydroxymethylation and asymmetric reduction or transamination were then combined with the chemocatalytic hydration of acrolein in a one-pot process to synthesize optically pure 1,2,4-butanetriol and 2-aminobutane-1,4-diol from acrolein and formaldehyde. These results exemplify a new way for sustainable synthesis of high value-added chemicals from C1 molecules and simple starting materials.
研究领域:
化学工程
·
生物化学
·
生物技术
·
有机化学
✓ 已验证
DOI
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2020
·Vol. 167
·期 10
·100548
·
IF 3.721
Yingying Zhang,Liming Xu,Jingkun Xu,Weiqiang Zhou,Hui Zhang
Poly(3,4-ethylenedioxythiophene) and its derivatives provide an excellent platform as electrode materials for supercapacitors due to their superior stability and conductivity. In this study, a poly(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methanol (PEDOT-MeOH) porous nanonet (PEDOT-MeOH-PNN), PEDOT-MeOH hollow nanotube array (PEDOT-MeOH-HNA) and PEDOT-MeOH-PNN coated PEDOT-MeOH-HNA (PEDOT-MeOH-PNN@PEDOT-MeOH-HNA) are successfully fabricated using a template-free electrodeposition of (2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methanol monomer. These three nanostructures were studied by Fourier transform infrared spectrum and Raman spectrum, scanning electron microscopy, thermal analysis and electrochemical methods, respectively. PEDOT-MeOH-PNN@PEDOT-MeOH-HNA has a specific capacitance of 40.5 mF cm−2 at 40 mV s−1, which is higher than PEDOT-MeOH-PNN (21.6 mF cm−2) and PEDOT-MeOH-HNA (35.5 mF cm−2). Moreover, the PEDOT-MeOH-PNN@PEDOT-MeOH-HNA based symmetric supercapacitor delivers excellent rate performance and superior cycling stability (90% of the initial capacitance remains after 10,000 cycles). The results indicate that the structural design of a supercapacitor electrode can improve their electrochemical performance, and promote the application and development of conducting polymers in the field of supercapacitors.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
BIOORGANIC & MEDICINAL CHEMISTRY
·
2024
·
IF 3.3
Li Guan,Yanxin Xia,Pengfei Song,Huiru Zhao,Shengjie Zhang,Wanzhen Su,Aiyun Li,Weize Li
In this paper, we investigated the anticancer effect and the mechanism of our newly synthesized bibenzyl 8Ae against human lung cancer A549 cells. Compound 8Ae could induce apoptosis by inhibiting the glycolysis in A549 cells. Hexokinase 2 (HK2), the first key enzyme in glycolysis process, was significantly down-regulated by 8Ae. Besides, compound 8Ae induced HK2 dissociated from mitochondria to cytosol, which could be induced by inhibiting the phosphorylation of Akt. In addition, 8Ae could induce mitochondrial-mediated apoptosis, and mitochondrial membrane potential (MMP) was decreased. After 8Ae treatment, the Bax/Bcl-2 ratio was increased and cytochrome c (Cyt c ) was release from mitochondria to cytosol. Molecular docking indicated that 8Ae have an interaction with HK2 by extending into acitve pockets of the protein to form stable hydrogen bonds. Additionally, 8Ae had significantly improved pharmacokinetic properties through the prediction, comparison, and analysis of the ADMET properties of 8Ae and moscatilin (MST). Taken together, 8Ae might inhibit glycolysis by stimulating the shedding of HK2 from mitochondria and promoting mitochondria-regulated apoptosis to inhibit the proliferation of A549 cells. This article provides a research basis for bibenzyl compounds as new small molecule drugs for lung cancer.
研究领域:
肿瘤学
·
药理学
·
细胞生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Chuan Lai,Hongxia Yang,Xiaogang Guo,Xiulan Su,Lvshan Zhou,Lei Zhang,Bin Xie
The new organic corrosion inhibitor of 2-( p -bromobenzylthio)-1 H -benzimidazole (Br-BBD) was synthesized in this work. After prepared, the adsorption and corrosion inhibition performance of Br-BBD for Q235 steel in HCl solution were studied using EIS, SEM, polarization measurement and WLM (weight loss measurement). The results exhibit that Br-BBD acts as an excellent corrosion inhibitor for Q235 steel in HCl solution, and the inhibition efficiency can reach up to 98.07% when the Br-BBD concentration is 50 mg L -1 in 1.0 M HCl at 25°C. In addition, the adsorption of the mixed-type inhibitor of Br-BBD on Q235 steel surface obey Langmuir adsorption isotherm, which is governed by spontaneous chemisorption mechanism.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 40
·e202303078
·
IF 2.1
Yixin Tong,E. Mi,Li Zhou,Xiabin Wang,Biao Xiong
Graphical The synthesis of 2-acylindoles from sulfoxonium ylides with o-aminoaryl aldehydes via iridium-catalyzed N−H insertion and intramolecular condensation has been demonstrated. 2-Acylindoles possess widespread applications in functional chemicals. However, the convenient and selective synthesis of such important substructures has to date remained a challenge. Herein, a method to achieve 2-acylindoles from sulfoxonium ylides with o-aminoaryl aldehydes catalysed by Iridium has been developed with the merits of broad substrate scope, good functional tolerance, high efficiency and operational simplicity, which provides an alternative way to access functionalized indoles.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE-POLAND
·
2024
·Vol. 42
·期 2
·70-80
·
IF 1.3
Yanling Yu,Biwu Huang,Yafen Qu,Junshan Qiu,Yong Lai
[2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane was synthesized, using triphenylsilane and 1,2-epoxy-4-vinylcyclohexane as the main raw materials. When the molar ratio of triphenylsilane to 1,2-epoxy-4-vinylcyclohexane was 1.0:1.2, the content of Wilkinson catalyst was 0.4%, the reaction temperature was 90°C, and the reaction time was 6 hours, the yield of [2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane could reach 95.21%. The structure of the synthesized product was analyzed and characterized using FT-IR and 1H-NMR. The synthesized product was added to a bisphenol A-type epoxy resin (E-51) and a modified amine (593 amine) to prepare an adhesive. Then, the adhesive was poured into the mold and cured at 35°C for 8 hours. The cured sample exhibited the best performance when the ECETPS: E-51:593 amine molar ratio was 0.8:7.2:2. Thermal gravimetric analysis (TG) showed that the thermal stability of the cured samples increased relative to pure E-51 amine-cured samples with the synthesized product added. The mechanical properties of the samples were tested using a universal material testing machine, and the results showed a tensile strength of 37.95 MPa and a bending strength of 39.10 MPa.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）