FOLIA MICROBIOLOGICA
·
2015
·Vol. 61
·期 3
·249-253
·
IF 1
Hu Ruixue,Du Na,Chen Nan,Lin Li,Zhai Yanhua,Gu Zemao
The mechanisms of resistance to levofloxacin for Aeromonas hydrophila isolated from diseased fish and selected in vitro were examined in this study. Levofloxacin-resistant mutants were obtained by selection of A. hydrophila in vitro. The quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were sequenced in Lev R strains and reverse mutation strains. All Lev R strains carried a point mutation at codon 83 (Ser → Ile), and one strain (25 %) harbored a mutation at position 92 (Leu → Met) in the GyrA-QRDR. After being transferred in a levofloxacin-free medium, one strain of the mutants was successfully reversed and the reversion was related with mutations o f GyrA-QRDR at positions 81 (Gly → Asp) and 83 (Ile → Ser). No amino acid alteration was found in the ParC-QRDR. In addition, the minimum inhibitory concentration (MIC) of levofloxacin for the mutants was lower in the presence of reserpine, and all mutants were also resistant to some of the other quinolones. It was found that the mechanism of levofloxacin resistance of A. hydrophila selected in vitro was related to gyrA of type II topoisomerase, and an efflux mechanism was involved in the resistance as well.
研究领域:
微生物学
·
分子生物学
·
药理学
·
水产病害防治
·
抗菌药物耐药性
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DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Yang Yuan,Jiaxin Wang,Xinjiong Ni,Yuhua Cao
A biosensor for determination of 3-chloro-1, 2-propandiol (3-MCPD) was developed based on the electrochemically catalytic reduction by hemoglobin (Hb). Hb was concentrated and immobilized with magnetic molecularly imprinted nanoparticles (MMIPs NPs). The MMIP NPs had a core-shell structure, with magnetic Fe 3 O 4 NPs as the core and SiO 2 as the shell. MMIPs NPs were modified on the surface of a magnetic electrode to constitute the Hb enzyme-like sensor. The biosensor could catalyze the electrochemical reduction of 3-MCPD, and a direct electrochemical determination of 3-MCPD could be achieved for the first time. The biosensor, where Hb immobilized with MMIPs NPs had high electrochemical response for 3-MCPD, increased by 37.5% compared with Hb immobilized with magnetic non-imprinted nanoparticle (MNIPs NPs). The biosensor increased the response by 19.56% again under an external magnetic field . The reduction peak current had a linear relationship with 3-MCPD concentration ranging from 1.0 mg·L −1 to 160 mg·L −1 with a detection limit (S/N = 3) of 0.25 mg·L −1 . The biosensor was applied to the determination of 3-MCPD in soy sauce samples successfully with recoveries between 97.4% and 99.6%.
研究领域:
生物传感器
·
分析化学
·
食品科学
·
电化学
·
分子生物学
·
纳米医学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2014
·
IF 2.694
Guihua Ruan,Meiping Wei,Zhengyi Chen,Rihui Su,Fuyou Du,Yanjie Zheng
A novel large-volume immobilized enzyme reactor (IMER) on small column was prepared with organic–inorganic hybrid silica particles and applied for fast (10 min) and oriented digestion of protein. At first, a thin enzyme support layer was formed in the bottom of the small column by polymerization with α-methacrylic acid and dimethacrylate. After that, amino SiO 2 particles was prepared by the sol–gel method with tetraethoxysilane and 3-aminopropyltriethoxysilane. Subsequently, the amino SiO 2 particles were activated by glutaraldehyde for covalent immobilization of trypsin. Digestive capability of large-volume IMER for proteins was investigated by using bovine serum albumin (BSA), cytochrome c (Cyt- c ) as model proteins. Results showed that although the sequence coverage of the BSA (20%) and Cyt- c (19%) was low, the large-volume IMER could produce peptides with stable specific sequence at 101–105, 156–160, 205–209, 212–218, 229–232, 257–263 and 473–451 of the amino sequence of BSA when digesting 1 mg/mL BSA. Eight of common peptides were observed during each of the ten runs of large-volume IMER. Besides, the IMER could be easily regenerated by reactivating with GA and cross-linking with trypsin after breaking the –C N– bond by 0.01 M HCl. The sequence coverage of BSA from regenerated IMER increased to 25% comparing the non-regenerated IMER (17%). 14 common peptides. accounting for 87.5% of first use of IMER, were produced both with IMER and regenerated IMER. When the IMER was applied for ginkgo albumin digestion, the sequence coverage of two main proteins of ginkgo, ginnacin and legumin, was 56% and 55%, respectively. (Reviewer 2) Above all, the fast and selective digestion property of the large-volume IMER indicated that the regenerative IMER could be tentatively used for the production of potential bioactive peptides and the study of oriented protein digestion.
研究领域:
生物化学
·
分子生物学
·
蛋白质组学
·
酶工程
·
生物材料
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DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 66
·38003-38012
·
IF 2.936
Xiuqiong Chen,Huiqiong Yan,Wei Sun,Guangying Chen,Changjiang Yu,Wen Feng,Qiang Lin
To achieve the dispersion of the hydrophobic graphene (GR), the amphiphilic alginate caprylamide (ACA) was synthesized to fabricate electroactive Nafion/Mb–ACA–GR/CILE for the accurate determination of trichloroacetic acid (TCA). SEM observation, FT-IR and UV-Vis spectroscopic analysis indicated that ACA could tightly immobilize Mb and GR on the electrode surface by constructing biointerfaces, which not only provided Mb a suitable microenvironment to maintain its biological activity, but also shortened the distances between the active centers of Mb with carbon ionic liquid electrode (CILE), thus promoting the electron transfer rate. The electrochemical characterization of Nafion/Mb–ACA–GR/CILE showed that the direct electron transfer of Mb was realized on the modified electrode, which was attributed to the high electrical conductivity and excellent electrocatalytic activity of GR and good biocompatibility of ACA. Moreover, Nafion/Mb–ACA–GR/CILE exhibited good electrocatalytic activity towards TCA with the linear range from 2.5 to 47.3 mmol L−1 and lower KMapp value of 8.3 mmol L−1. Moreover, the modified electrode also revealed good stability, reproducibility and accurate detection of tap-water, exhibiting great potential for the applications as the third-generation electrochemical biosensors.
研究领域:
生物医学工程
·
电化学传感
·
纳米生物技术
·
分子生物学
·
分析化学
·
生物传感器
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DOI
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 17
·8278-8283
·
IF 4.197
Zhiqiang Ye,Quankun Gao,Xin An,Bo Song,Jingli Yuan
A unique ruthenium(II) complex, [Ru(bpy)2(DNS-bpy)](PF6)2 [bpy: 2,2′-bipyridine, DNS-bpy: 4-(2,4-dinitrophenylthio)-2,2′-bipyridine], that can act as a probe for the recognition and luminescence sensing of biothiols has been designed and synthesized. Due to the presence of effective photo-induced electron transfer (PET) from the potent electron donor (Ru-bpy centre) to the strong electron acceptor (2,4-dinitrophenyl moiety), the Ru(II) complex itself is weakly luminescent. Reaction of [Ru(bpy)2(DNS-bpy)](PF6)2 with biothiols leads to the replacement of the 2,4-dinitrophenyl moiety by biothiols, which results in the loss of PET within the complex, to allow recovery of the MLCT-based emission of the Ru(II) complex with an 80-fold increase in luminescence intensity. Taking advantage of the high specificity and sensitivity, and the excellent photophysical properties of Ru(II) complexes, [Ru(bpy)2(DNS-bpy)](PF6)2 was successfully applied to the luminescence imaging of biothiols in living Daphnia magna. The results demonstrated the practical applicability of [Ru(bpy)2(DNS-bpy)](PF6)2 as a luminescent probe for the monitoring of biothiols in living bodies.
研究领域:
分析化学
·
分子生物学
·
化学生物学
·
生物成像
·
无机化学
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DOI
高影响因子
Advances in Experimental Medicine and Biology
·
2016
·
IF 1.953
Yan Heping,Chen Yashun,Zhang Jucheng,Liu Wei,Chen Rui
The first derivatives of gelatin and type I collagen fluorescence spectra were characterized in order to describe the effect of free radicals on pyridinoline (PYD) cross-links. The different gas saturation conditions were used to investigate the effect of different free radicals. An analysis of first derivative fluorescence spectra suggests that PYD cross-link fluorescence emission is composed of three peaks in gelatin, but only two in type I collagen. The PYD cross-link was photo-degraded more than other gases in the presence of O 2 . This suggests that the singlet oxygen ( 1 O 2 ) plays a key role when using photodynamic therapy to treat skin fibrosis disease with Hypocrellin B (HB).
研究领域:
光生物学
·
皮肤科学
·
分子生物学
·
结缔组织病
·
自由基化学
·
光动力学
·
纤维化疾病
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Shanshan Zhang,Xuerui Chen,Shiping Ding,Qunfang Lei,Wenjun Fang
The interactions of human serum albumin (HSA) with four cationic gemini surfactants and four single-chain surfactants have been investigated from the measurements of fluorescence spectroscopy, dynamic lights scattering (DLS), zeta potential, and circular dichroism (CD). The fluorescence results show the binding strength of surfactants to HSA, along with the blue shift under the maximum emission wavelength ( λ max ) which is sensitive to the protein conformations. It has been found that the hydrodynamic diameters of the protein aggregates are enlarged and the electrokinetic potentials of them get positive with increasing the concentration of the surfactants. The conformational transformation of the secondary structures of surfactant–HSA aggregates has been confirmed through the quantitative analysis of the CD spectra. The isothermal titration microcalorimetry (ITC) has been employed to further analyze the binding process of single-chain surfactants to HSA. The comprehensive results obtained from various approaches have shown that both hydrophobic and electrostatic interactions are present in the cationic surfactant–HSA systems. Compared with the corresponding single-chain surfactants, the gemini ones have much stronger binding ability to induce the unfolding of HSA. These investigations on the interactions between HSA and surfactants with the altered chain architecture in different concentration regimes can facilitate the application of surfactant-protein systems in pharmaceutical, biotechnology and related fields.
研究领域:
生物物理化学
·
分子生物学
·
药剂学
·
蛋白质科学
·
药物代谢
·
胶体与界面科学
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DOI
高影响因子
Journal of Analytical Science and Technology
·
2021
·Vol. 12
·期 1
·18
·
IF 2.769
Chen Kangni,Li Yanbo,Shang Jinyan,Zhao Chao,Li Heping
Ozone is widely used in daily life, but studies have shown that O 3 can damage human trachea and lungs, leading to diseases such as asthma, emphysema, and bronchitis. Therefore, it is of great significance to develop a simple and efficient detection method for monitoring O 3 in living cells. In this study, 3-(but-3-en-1-yl)-2-(7-(but-3-en-1-yloxy)-2-oxo-2H-chromen-3-yl)benzo[d]thiazol-3-ium (BCT) as a new type of water-soluble fluorescent probe was synthesized by substitution reaction of 4-bromo-1-butene and hydroxycoumarin-benzothiazole derivatives, which can specifically detect ozone in aqueous solution. The interaction of ozone on the probe can be completed within 20 min, the fluorescence intensity is significantly enhanced, and it has the advantages of high sensitivity (detection limit LOD = 43 nM). The influence of pH on the fluorescent performance of BCT shows that the probe with super stability under weak alkali and acidic environment, which provides the necessary conditions for its detection of ozone in physiological system detection. Therefore, BCT is expected to become an effective tool for detecting ozone in cellular organisms.
研究领域:
分析化学
·
分子生物学
·
环境毒理学
·
生物医学工程
·
细胞生物学
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DOI
高影响因子
OPTICAL FIBER TECHNOLOGY
·
2013
·Vol. 20
·期 1
·28-31
·
IF 1.187
Jiao-Yang Li,Xu-Guang Huang,Wei Xu,Dong-Rui Xiao,Ze-Bing Zhong
A biocompatible fiber-optic pH sensor based on Fresnel reflection technique and a sensing coating is presented. Sodium alginate and polyethylenimine are alternatively deposited on the sensing fiber end to form the sensing coating via a layer-by-layer electrostatic self-assembly technique. An optical switch is added to the measurement system for the convenience of fast calibration. A linear, monotonic and fast response in a large pH range (from pH 5.87 to pH 10.55) is obtained with the resolution of 0.01 pH unit. The sensitivity of the pH sensor is 0.018 R.I.U/pH. It is not influenced by fluctuations of light source.
研究领域:
生物医学工程
·
传感技术
·
分子生物学
·
转化医学
·
生物材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR RECOGNITION
·
2016
·Vol. 30
·期 1
·e2566
·
IF 2.091
Hua-jin Zeng,Min Miao,Ran Yang,Ling-bo Qu
In this study, the fibrillation of hen egg-white lysozyme (HEWL) in the absence and presence of different concentrations of silybin was studied by thioflavin T spectroscopy, Congo red binding assays, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence assay, circular dichroism, and transmission electron microscopy. The experimental results indicated that not only the fibrillation of HEWL at high temperature (65°C) and low pH (pH = 2.0) could be inhibited effectively by silybin but also the inhibition of HEWL by silybin followed a dose-dependent manner. Molecular docking studies indicated that 2 possible binding modes could be found in the interaction between silybin and HEWL via van der Waals forces and electrostatic forces as well as hydrogen bonding. One of these 2 conformations was directly entered into the cavity of HEWL (binding site I); the other was bound to the surface of HEWL (binding site II). In this way, silybin could not only increase the hydrophobicity of the cavity or the surface of HEWL but also influence the microenvironment of the binding site, which was able to stabilize the structure of HEWL and delay the process of HEWL fibrosis.
研究领域:
生物化学
·
分子生物学
·
蛋白质科学
·
药理学
·
结构生物学
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DOI
高影响因子
Biomed Research International
·
2015
·Vol. 2015
·期 1
·139179
·
IF 1.579
Jingjing Sun,Yiling Chen,Jun Sheng,Mi Sun
To improve the reusability and organic solvent tolerance of microbial lipase and expand the application of lipase (hydrolysis, esterification, and transesterification), we immobilized marine microbial lipase using different methods and determined the properties of immobilized lipases. Considering the activity and cost of immobilized lipase, the concentration of lipase was fixed at 2 mg/mL. The optimal temperature of immobilized lipases was 40°C and 5°C higher than free lipase. The activities of immobilized lipases were much higher than free lipase at alkaline pH (more than 50% at pH 12). The free lipase lost most activity (35.3%) and immobilized lipases retained more than 46.4% of their initial activity after 3 h heat treatment at 70°C. At alkaline pH, immobilized lipases were more stable than free lipase (more than 60% residue activity at pH 11 for 3 h). Immobilized lipases retained 80% of their activity after 5 cycles and increased enzyme activity (more than 108.7%) after 3 h treatment in tert-butanol. Immobilization of lipase which improved reusability of lipase and provided a chance to expand the application of marine microbial lipase in organic system expanded the application range of lipase to catalyze hydrolysis and esterification in harsh condition.
研究领域:
酶工程
·
分子生物学
·
生物催化
·
工业微生物学
·
蛋白质化学
·
应用酶学
✓ 已验证
DOI
高影响因子
Plasma Processes and Polymers
·
2011
·Vol. 8
·期 10
·923-931
·
IF 1.643
Zhihong Zhang,Jun Dou,Fufeng Yan,Xianjun Zheng,Xili Li,Shaoming Fang
The present work describes the fabrication, characterization, and optimization of plasma polymerized pyrrole films, PPpy, prepared by continuous wave for application as the adhesion layers of bovine serum albumin (BSA). Plasma conditions used throughout the work produced significant differences in the chemical, physical, and electrochemical properties of the resultant PPpy films. Structural analysis and property characterizations of PPpy were carried out using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical workstation. Surface plasmon resonance spectroscopy was used to investigate the adsorption kinetics of BSA onto PPpy films. Moreover, when immersed in solutions or after BSA adsorption, the differences of electron transfer at the interfaces between the PPpy and the electrolyte solutions were determined by electro impedance spectroscopy. While there is a clear dependence of the protein adsorption affinity on the plasma polymerization condition employed during the film preparation. The relationship between film structure, electrochemical properties, polymer stability in aqueous buffer, and protein binding affinities are discussed.
研究领域:
生物材料
·
表面科学
·
生物医学工程
·
分子生物学
·
分析化学
·
生物传感器
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DOI
高影响因子
危险品化学品经营许可证（带存储）