BIOMEDICINE & PHARMACOTHERAPY
·
2019
·
IF 3.743
Lu Gao,Jia-Hua Zhang,Xiao-Xu Chen,Hui-Li Ren,Xiu-Ling Feng,Jia-Ling Wang,Jun-Hua Xiao
Pulmonary fibrosis (PF) progression may be involved with arginine (Arg) metabolism and immune balance. The present study aimed to explore the effects of L-Arginine (L-Arg) and L-Norvaline (L-Nor) on bleomycin (BLM)-induced PF in mice, meanwhile, and observe dynamic changes of Arg metabolism, immune balance and crosstalk between them in PF progression. Followed intratracheal instillation of BLM or saline, Kunming mice were treated orally with saline, L-Arg, L-Nor and L-Arg + L-Nor three times a day. And the mice were sacrificed on Day 3, 14 and 28 after treatment. Changes of body weight, lung index, lung hydroxyproline and histopathology were analyzed to evaluate the PF degree. Peripheral blood Arg, Citrulline (Cit), Ornithine (Orn) and Proline (Pro), lung NO, NOS and arginase were analyzed to evaluate the Arg metabolism. Peripheral blood Tregs, Th17 and γδT cells were analyzed to evaluate the immune balance. Our data showed that combination of L-Arg and L-Nor dynamically reversed the weight loss, decreased lung index and hydroxyproline, and improved lung histopathological damages induced by BLM. The combination dynamically and significantly rectified Tregs, Th17, γδT and Tregs/Th17 abnormal changes. Meanwhile, these disorders of peripheral blood Arg, Cit, Orn, Pro, Orn/Cit and Pro/Orn, and lung NO, iNOS and TNOS were also improved accordingly. These results demonstrated that combination of L-Arg and L-Nor had inhibitory effects on BLM-induced PF progression, possibly due to their corrective action on immune imbalance, Arg metabolism disorder and crosstalk abnormality in the progression of PF.
研究领域:
药理学
·
免疫学
·
肺病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2024
·
IF 3.4
Yuguang Wang,Mengjing Wu,Huifang Zheng,Dongmei Wu,Panpan Yao,Wenjing Li,Kexin Jin,Xinjun Yu
A strain high-performance of esterase producing bacteria was screened from soil, which could selectively hydrolyze D -homoserine lactone from its racemate to achieve the resolution of L - homoserine lactone with more than 99% e.e. in 48% yield. L -homoserine lactone building block was then converted to L -α-amino-γ-bromobutyronic acid chiral blocks, which reacted with various nucleophilic reagent modules could to be applied to prepare L -γ- substituted α-amino acids such as L -selenomethionine, L -methionine, L -glufosinate and L -selenocystine. Its advantages included high selectivity of biocatalytic resolution reactions, high optical purity of products, racemic recycle of D -substrates and modular reaction, which simplified the production process of these products and highlighted the power of biological manufacturing.
研究领域:
生物化学
·
生物制造
·
酶工程
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产品关联
DOI
PubMed
高影响因子
ELECTROPHORESIS
·
2012
·Vol. 34
·期 3
·409-416
·
IF 3.303
Juan Qiao,Li Qi,Huijuan Yan,Yaping Li,Xiaoyu Mu
l -Asparaginase ( l -Asnase) can suppress the growth of malignant cells by rapid depletion of two essential amino acids, l -glutamine ( l -Gln) and l -asparagine ( l -Asn). To study the cytotoxic effect and the secondary complications of l -Asnase in the treatment of acute lymphoblastic leukemia, the development of a novel enzyme reactor of l -Asnase for the hydrolysis of l -Gln, employing the enzyme-gold nanoparticle conjugates in capillary, was reported in this work. First, a microchip CE (MCE)-LIF was established for the separation of l -amino acids ( l -Gln and l -glutamic acid) and studying the hydrolysis of l -Gln by using l -Asnase enzyme reactor. Then, using l -Gln as target analyte, the enzyme kinetics of l -Asnase in free solution, enzyme-gold nanoparticle conjugates (E-GNP), and the enzyme-gold nanoparticle conjugates immobilized in capillary (E-GNP-C) were investigated in detail with the proposed MCE-LIF method. Moreover, for optimizing the enzymatic reaction efficiency, three important parameters, including the length of capillary, the enzyme concentration reacted with gold nanoparticle and the amount of l -Asnase immobilized on the gold nanoparticle, have been studied. Owing to the high specific activity, the E-GNP-C enzyme reactor exhibited the best performance for the hydrolysis of l -Gln.
研究领域:
生物化学
·
医学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
BIOELECTROCHEMISTRY
·
2012
·
IF 3.759
Xiao Liu,Liqiang Luo,Yaping Ding,Zhangping Kang,Daixin Ye
A novel Au-nanoparticles/poly-eriochrome black T film modified glassy carbon electrode (AuNPs/PEBT/GCE) was constructed for the simultaneous determination of l -cysteine (L-Cys) and l -tyrosine (L-Tyr) by differential pulse voltammetry . Fourier transform infrared spectra and electrochemical impedance spectroscopy indicate that the PEBT film was successfully polymerized on the surface of GCE and the film efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analytes and electrode. The scanning electron microscope image shows that the immobilized AuNPs were spherical in shape and enhanced the electrical conductivity of PEBT film. In addition, PEBT film increased the oxidation currents of analytes four times when compared to bare GCE, and the AuNPs separated the oxidation potentials of L-Cys and L-Tyr by 488 mV while bare GCE failed to resolve them. The amperometry results exhibit that the electrocatalytic currents increased linearly with L-Cys concentrations in the range 0.05–100 μM ( r = 0.9981), and the detection limits of L-Cys and L-Tyr were 8 nM and 10 nM ( S / N = 3), respectively. With high sensitivity and selectivity, the proposed electrochemical sensor provides a simple method for simultaneous determination of L-Cys and L-Tyr.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2023
·Vol. 365
·期 7
·1048-1057
·
IF 5.4
Xiao-Ling Tang,Ning Li,Yan-Lai Liu,Jing-Peng Li,Kai-Xuan Zhao,Zhi-Qiang Liu,Yu-Guo Zheng
L-Methionine is the unique sulfur-containing amino acid essential for humans and animals, which is widely used in pharmaceutical, food and feed industries. Its green and efficient production has attracted a great deal of attention. Fermentation-enzymatic coupling route is regarded to be promising for L-methionine biosynthesis, while O- succinyl-L-homoserine mercaptotransferase (MetZ) is the key biocatalyst. Exploring and engineering of MetZ with ideal catalytic properties is highly desired. Herein, the MetZ from Chromobacterium violaceum ( Cv MetZ) was screened and through in silico analyses, potential beneficial amino acid residues both at the access channel and around the oxygen anion holes were anchored for site-saturation mutagenesis. The positive mutants were obtained with improved activity for L-methionine biosynthesis using O -succinyl-L-homoserine (OSH) and methyl mercaptan as substrate. The best mutant was further applied for L-methionine production and supply of methyl mercaptan was optimized in a fed-batch approach. The conversion of 100 g/L OSH reached 92% with L-methionine yield of 62.6 g/L, which was well coupled with the OSH fermentation level.
研究领域:
生物化学
·
合成生物学
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zhikun Zhang,Liwei Bai,Heli Tian,Jilong Han,Kunjie Li,Zhengjie Li,Qingju Liu
Fluorescent metal–organic frameworks (FMOFs) hold great promise for detecting biomolecules, but a comprehensive understanding of their response mechanisms is still challenging to guide the design of assays. Herein, we creatively proposed fluorescent analysis via the hydrogen-bond-triggered enhanced fluorescence effect between the oxygen of a carboxyl group of targets and an amino group of ligands in the FMOFs in an aqueous solution. Based on the above strategy, we synthesized the Ru@ZrMOF and constructed a ratiometric fluorescent and colorimetric dual-readout method for a simple and rapid platform to selectively detect amino acids. Taking l -glutamic ( l -Glu) and l -aspartic acid ( l -Asp) as examples, the introduction of l -Glu and l -Asp sharply increased the fluorescent value at 450 nm through strong hydrogen bonding, leading to a difference in the color from red to blue. Data from computational simulations point to the presence of strong hydrogen bonds between l -Glu/ l -Asp and FMOFs. Dual-mode fluorescent/colorimetric method selectively and accurately detects l -Glu acid and l -Asp within 30 min. The detection range for the two was found to be between 5 μM and 2 mM, with detection limits of 3 μM and 2.5 μM, respectively. In addition, a paper-based platform was fabricated and a logic gate was developed for the rapid and visual measurement of l -Glu and l -Asp. This platform is simple, quick, easy to use, and sensitive, making it a promising tool for future applications in amino acid detection, particularly in biological samples.
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 17
·3481-3487
·
IF 1.915
Lili Wang,Wencheng Gong,Fang Wang,Zhenya Yu,Zilin Chen
An efficient bienzyme nanocomposite film-based biosensor for L-amino acid recognition has been developed and characterized. The biosensor was fabricated by immobilizing horseradish peroxidase (HRP) and L-amino acid oxidase (L-AAODx) in poly(toluidine blue) film (polyTB) at the surface of a multi-walled carbon nanotube (CNTs) modified glassy carbon electrode (GCE). Only L-amino acids can be electrochemically oxidized by L-AAODx in the presence of oxygen (O2) to produce hydrogen peroxide (H2O2), which can be further reduced to H2O by HRP at a low potential of −0.1 V. The concentration of L-amino acids was estimated by the reduction current of H2O2. The polyTB film, acting as the enzyme-immobilization carrier and redox mediator, accelerated electron transfer between analytes and the electrode. At the same time, CNTs with excellent conductivity and strong adsorption ability enhanced the utilization of the enzymes. The performance of this biosensor was evaluated by electrochemical techniques and it showed high selectivity and fast response for the chiral recognition of L-amino acids, including L-tryptophan (L-Trp), L-phenylalanine (L-Phe) and L-tyrosine (L-Tyr). The low potential reduced the interference of some coexisting biomolecules for the determination of the L-amino acids. The recovery of the three amino acids in milk indicated the feasibility of this biosensor for use in complex samples.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
BIOMEDICAL CHROMATOGRAPHY
·
2020
·Vol. 35
·期 3
·e4991
·
IF 1.728
Li-Juan Nie,Jun Liang,Feng Shan,Ya-Yun Xu,Chun-Yu Yan,Xuan Zhou,Zhuo-Yu Cheng,Qing-Rong Xia
A simple, rapid, and selective ultra-performance liquid chromatography–tandem mass spectrometry method for determination of l -carnitine (LC) and acetyl- l- carnitine (ALC) in human serum was developed. Acetyl- l- carnitine-d 3 (ALC-d 3 ) was selected as internal standard (IS). After protein precipitation with acetonitrile–water (1 mL, 2:1, v/v), the analytes and IS were separated on a 2.5-μm XSelect HSS T3 C 18 column by gradient elution with methanol–water (containing 0.01% ammonia water) as the mobile phase at a flow rate of 0.2 mL/min. Analytes were detected with multiple reaction monitoring using a positive scan mode with electrospray ionization. Good linearity ( R 2 > 0.999) was observed in the concentration range for LC and ALC. The inter- and intra-day values of relative error were −10.4% to 10.0% with CVs less than 9.84%. The average recoveries of the two analytes were 91.29%–98.23%. Blood samples containing LC and ALC were stable under various storage conditions. Normal, haemolytic, and hyperlipidaemic serum had no significant effect on the quantification of LC and ALC. This method was successfully applied to study the concentrations of endogenous LC and ALC in the serum of patients with first-episode depression.
研究领域:
分析化学
·
医学
·
精神健康研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 11
·45984
·
IF 1.86
Ying Yue,Zhihui Fan,Chang Zheng,Lan Ding,Huiying Wang,Miao Zhang,Kuilin Deng
In this investigation, a group of poly( l -malic acid acetate- co - l -lysine ester)s (PMALs) with excellent thermo-sensitivity and non-cytotoxicity were prepared by an optimized synthetic route from natural l -malic acid and l -lysine. The structure and properties of PMALs including monomers were systematically characterized by FTIR, 1 H NMR, UV, gel permeation chromatograph, scanning electron microscope, contact angle measurement, cell counting kit assess (CCK-8), and confocal laser scanning microscopy (CLSM). Three PMALs show a reversible lower critical solution temperature of 8–36 °C depending on their chemical structure. The contact angle measurement revealed a considerable discrepancy in the hydrophilicity/hydrophobicity of PMALs and further influence on their thermo-sensitivity. The viability of HeLa cells exposed to 0.2–100 μg/mL PMALs solution was found to be in a range 80–103% after 24, 48, and 72 h of incubation, indicating no cytotoxicity. Moreover, a spherical nanocarrier with core-shell structure was facilely fabricated via the thermo-sensitivity of PMALs and hydrophobicity of drug. CLSM observations manifested that the hydrophobic-curcumin-enwrapped nanocarriers can clearly internalize into the cellular inside. The sustained release of curcumin from nanocarriers in vitro provided a possibility of depressing fast hydrolytic degradation at physiological pH or other side-effects. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45984.
研究领域:
生物材料学
·
药物递送系统
·
高分子化学
✓ 已验证
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2024
·
IF 3.7
Shaoyang Zhang,Guorong Zhu,Zhixiang Pan,Yi Wei,Zuoming Nie,Qing Sheng,Zhongyi Yang
L-threo-methylsulonylphenylserine (L-threo-MSPS) is a crucial intermediate in florphenicol and thiamphenicol synthesis. L-threo-MSPS can be synthesized from L-threonine and p-methylsulfonylbenzaldehyde (p-MSBA) chiral selectively under the catalyse of L-threonine transaldolase . However, the byproduct acetaldehyde formed during the reaction process severely hinders the biosynthesis of high-quality L-threo-MSPS. The accumulated acetaldehyde reacts with L-thero-MSPS and L-threonine to form N-derivatives, and the activity of L-threonine transaldolase decreases to 14.10% even when the concentration of acetaldehyde is as low as 0.5 g/L. The acetaldehyde could be removed by aeration, and the removal efficiency is closely related to the aeration conditions, which was described by the volumetric oxygen transfer coefficient k L a in this paper. Regular aeration through pipes cannot provide enough aeration efficiency, and filters or sintered rods were used to increase the k L a value during the reaction. The residual concentration of acetaldehyde depended on the balance between the formation and removal speed of acetaldehyde. When the optimal enzyme concentration was applied and the k L a value of 5.5 min -1 , the L-threo-MSPS concentration reached 293.28 mM in a 1-L reaction, and the highest conversion reached 90.03%. The need of coenzyme NAD + was cut off in this method, and only one enzyme was applied. Consequently, the reaction was simpler and easier to control.
研究领域:
生物化学
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2020
·
IF 5.339
Lili Liu,Peng Bao,Juan Qiao,Hongyi Zhang,Li Qi
Herein, D- and L-oligopeptides were explored for the first time as chiral ligands in a chiral ligand exchange capillary electrophoresis (CLE-CE) protocol with Zn(II) as central ion for separation of derived d , l -amino acid enantiomers (Dns-D,L-AAs). The effect of four D- and L-oligopeptides, including glycine- l -lysine (Gly-L-Lys), glycine- d -lysine (Gly-D-Lys), l -lysine-lysine-OH and l -lysine-lysine-lysine-lysine-OH on the CLE-CE separation efficiency were evaluated. Thermodynamic calculations and circular dichroism spectra properties showed that the ternary species [(Gly-L-Lys)Zn(II)(D-AAs)] and [(Gly-L-Lys)Zn(II)(L-AAs)] presented the best stereoselectivity , possibly due to entropic effects. Notably, the migration order of Dns-D-AAs and Dns-L-AAs could be tuned by using Gly-D-Lys as the ligand for the CLE-CE system. To obtain satisfactory CLE-CE performance, the concentration ratio of Zn(II) to Gly-L-Lys, the pH of the buffer solution, and the concentration of Zn(II) were investigated. Under the optimized CLE-CE conditions using 100.0 mM H 3 BO 3 , 10.0 mM NH 4 Ac, 3.0 mM Zn (II) and 12.0 mM Gly-L-Lys as the buffer solution at pH 8.30, nine pairs of Dns-D,L-AAs achieved baseline separation, with the partial separation of another five pairs. Furthermore, the proposed CLE-CE protocol, which presented a good linear relationship with the concentration of the test analytes in the range of 75.0–625.0 μM (r 2 ≥ 0.994) and the limit of detection of the method was 5.0 μM, was successfully applied in the kinetics study of l -asparaginase using l -asparagine as the substrate. Our strategy shows the great potential of L-dipeptides in the CLE-CE separation of D,L-AAs enantiomers and bio-applications.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2014
·Vol. 11
·期 3
·545-550
·
IF 4.151
Lei Yu,Wenxin Fu,Zhibo Li
Two series of copolymers were prepared by ring-opening polymerization (ROP) of γ-(2-methoxyethoxy)esteryl-L-glutamate (L-EG2Glu) N-carboxyanhydride (NCA) and L-alanine (L-Ala) using HMDS and PEG-NH2 as initiator, respectively. Poly-(L-EG2Glu-co-L-Ala) displayed lower critical solution temperature (LCST) behavior but had a lower phase transition temperature than poly-L-EG2Glu at similar molecular weight (MW). The clouding point (CP) of random copolypeptides can be tuned by altering the alanine content and overall MW. Circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) indicated that the thermal-responsive properties depended on the content of ordered conformations. PEG-b-poly-(L-EG2Glu-co-L-Ala) can spontaneously form hydrogels in water at room temperature. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that these hydrogels were formed by nanoribbons. The intermolecular hydrogen bonding among copolypeptide blocks accounted for the nanoribbon assemblies and hydrogel network formation.
研究领域:
聚合物化学
·
材料科学
·
生物物理学
✓ 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）