TALANTA
·
2014
·
IF 3.511
Xiaojuan Yang,Qingxin Han,Yange Zhang,Jiang Wu,Xiaoliang Tang,Chunxu Dong,Weisheng Liu
Two aptasensors based on graphene oxide (GO) and molecular beacon were designed for the detection of L-tryptophan (L-Trp) using L-Trp aptamer (Trp3a-1). The fluorescein (FAM) labeled Trp3a-1 was absorbed by GO, which resulted in the fluorescence quenching , and exhibiting minimal background fluorescence. Upon the addition of L-Trp, Trp3a-1 was not absorbed quickly. This effect allows for a quantitative assay of L-Trp over the concentration range of 10–500 μM and with a detection limit of 6.84 μM. However, due to the unspecific adsorption of GO, the GO based aptasensor can׳t be applied in complex matrixes. In respect of molecular beacon based aptasensor, FRET between Trp3a-1 labeled with FAM and CS-Trp3a-1 labeled with BHQ-1(black hole quencher-1) which is partially complementary with the aptamer was used to detect L-Trp. L-Trp binding could induce the disassociation of CS-Trp3a-1, resulted in the enhancement of fluorescence in solution. With an excellent linear relationship in 10–500 μM and a detection limit of 6.97 μM in 25% serum, the aptasensor is expected to be improved for the detection of free L-Trp in other complex samples.
研究领域:
生物化学
·
分析化学
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医学检测
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DOI
PubMed
高影响因子
CHIRALITY
·
2015
·Vol. 27
·期 9
·643-649
·
IF 1.886
Yao Wang,Jing Qiu,Wentao Zhu,Xinru Wang,Ping Zhang,Dezhen Wang,Zhiqiang Zhou
Myclobutanil, (RS)-2-(4-chlorophenyl)-2-(1H-1, 2, 4-triazol-1-ylmethyl) hexanenitrile is a widely used triazole fungicide. In this study, enantioselective metabolism and cytotoxicity were investigated in rat hepatocytes by chiral HPLC-MS/MS and the methyl tetrazolium (MTT) assay, respectively. Furthermore, tryptophan metabolism disturbance in rat hepatocytes after myclobutanil exposure was also evaluated by target metabolomics method. The half-life ( t 1/2) of (+)-myclobutanil was 10.66 h, whereas that for (−)-myclobutanil was 15.07 h. Such results indicated that the metabolic process of myclobutanil in rat hepatocytes was enantioselective with an enrichment of (−)-myclobutanil. For the cytotoxicity research, the calculated EC 50 (12h) values for rac -myclobutanil, (+)- and (−)-myclobutanil were 123.65, 150.65 and 152.60 µM, respectively. The results of tryptophan metabolites profiling showed that the levels of kynurenine (KYN) and XA were both up-regulated compared to the control, suggesting the activation effect of the KYN pathway by myclobutanil and its enantiomers which may provide an important insight into its toxicity mechanism. The data presented here could be useful for the environmental hazard assessment of myclobutanil. Chirality 27:643–649, 2015 . © 2015 Wiley Periodicals, Inc.
研究领域:
毒理学
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分析化学
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代谢组学
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DOI
PubMed
高影响因子
Chinese Journal of Natural Medicines
·
2026
·Vol. 24
·期 1
·59-72
·
IF 4.9
Yang Lin,Zhengmeng Jiang,Zhilu Yu,Tianqing Huang,Wanyu Gui,Ziyuan Wang,Fei Li,Pingting Xiao,Changyin Li,Ehu Liu
Diabetes mellitus (DM) is a chronic disease influenced by gut microbiome disturbances. Honokiol (HON), a low oral bioavailability compound from Magnolia officinalis bark, has demonstrated potential as a treatment for DM. This research investigates the effects of HON on gut microbiota and host metabolism to elucidate its mechanism of action in DM. After 8 weeks of intervention through fecal microbiota transplantation (FMT) or antibiotic treatment, HON improved glucose tolerance and lipid metabolism in a gut microbiota-dependent manner. Specifically, HON administration significantly increased Akkermansia muciniphila (AKK) abundance and modulated tryptophan (TRP) metabolism, as evidenced by 16S ribosomal ribonucleic acid (rRNA) gene sequencing and untargeted/targeted metabolomics analysis. Notably, research revealed that AKK metabolized TRP into tryptamine (TA) and other metabolites in vitro . Both AKK and TA activated the aryl hydrocarbon receptor (AHR) pathway, increasing circulating glucagon-like peptide-1 (GLP-1) levels and ameliorating diabetes-related symptoms in DM mice. These findings indicate that HON’s hypoglycemic effect primarily stems from AHR-GLP-1 pathway activation through targeted modulation of AKK and microbial TRP metabolite TA, potentially enhancing HON’s clinical applications.
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DOI
PubMed
高影响因子
Sensors & Diagnostics
·
2022
·Vol. 1
·期 5
·1080-1087
·
IF 0
Feng Wang,Hongye Wang,Xiaoqiang Cui,Yang Liu
Innovating the fluorescence characteristic of MXene nanosheets and quantum dots could result in fascinating perspectives in the applications of sensing, imaging and photocatalysis. However, the currently reported MXene-based materials have only shown down-conversion fluorescence emission, while the exploration and research of up-conversion fluorescent performance are scarce. Herein, the upconversion emission behaviors of Ti3C2 MXene nanosheets are reported and investigated for the first time. It was observed that the Ti3C2 nanosheets present upconversion emission in a wide wavelength range with adjustable color, covering almost the entire visible spectrum. The unique features of larger anti-stokes displacement (over 200 nm), narrower full width at half maximum (∼17 nm) and longer lifetime (1.18 μs) were also exhibited, which are superior to those of the down-conversion fluorescence. The self-quenched fluorescence of the Ti3C2 nanosheets on the side of the highest fluorescence emission was also displayed. Based on the quenching effect of L-tryptophan on the Ti3C2 fluorescence by a fast charge transfer mechanism, a fast, simple and label-free fluorescence sensor for L-tryptophan detection was realized with a detection limit as low as 91 nM, which provides a valuable tool to widen their applications in food safety and diagnostics.
研究领域:
材料科学
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生物医学工程
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分析化学
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DOI
Biotechnology for Biofuels and Bioproducts
·
2024
·Vol. 17
·期 1
·1-10
·
IF 3.3
Wang Lijuan,Deng Yongdong,Gao Jianjie,Wang Bo,Han Hongjuan,Li Zhenjun,Zhang Wenhui,Wang Yu,Fu Xiaoyan,Peng Rihe,Yao Quanhong,Tian Yongsheng,Xu Jing
Background The demand for melatonin is increasing due to its health-promoting bioactivities such as antioxidant and sleep benefits. Although melatonin is present in various organisms, its low content and high extraction cost make it unsustainable. Biosynthesis is a promising alternative method for melatonin production. However, the ectopic production of melatonin in microorganisms is very difficult due to the low or insoluble expression of melatonin synthesis genes. Hence, we aim to explore the biosynthesis of melatonin using Escherichia coli as a cell factory and ways to simultaneously coordinated express genes from different melatonin synthesis pathways. Results In this study, the mXcP4H gene from Xanthomonas campestris , as well as the HsAADC , HsAANAT and HIOMT genes from human melatonin synthesis pathway were optimized and introduced into E. coli via a multi-monocistronic vector. The obtained strain BL7992 successfully synthesized 1.13 mg/L melatonin by utilizing L-tryptophan ( l -Trp) as a substrate in a shake flask. It was determined that the rate-limiting enzyme for melatonin synthesis is the arylalkylamine N-acetyltransferase, which is encoded by the HsAANAT gene. Targeted metabolomics analysis of l -Trp revealed that the majority of l -Trp flowed to the indole pathway in BL7992, and knockout of the tnaA gene may be beneficial for increasing melatonin production. Conclusions A metabolic engineering approach was adopted and melatonin was successfully synthesized from low-cost l -Trp in E. coli . This study provides a rapid and economical strategy for the synthesis of melatonin.
研究领域:
微生物学
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代谢工程
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生物技术
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DOI
高影响因子
Heliyon
·
2023
·
IF 4
Habtamu Adefris Abebe,Abebe Diro,Shimeles Addisu Kitte
Herein, we reported carbon paste electrode modified with graphitic carbon nitride (g–C 3 N 4 –CPE) to determine of tryptophan (Trp) using voltametric techniques. Various spectroscopic and electrochemical techniques were used to characterize the as-synthesized g-C 3 N 4 and the assembled electrodes. The transfer coefficient, rate constant and the diffusion coefficient of Trp in this system were found to be 0.28, 1.9 × 10 4 M −1 s −1 and 3.2 × 10 −5 cm 2 s −1 , respectively. The linear range was obtained for the detection of Trp using LSV is from 0.1 μM to 120 μM at pH 5. The limit of detection (LOD) (3σ/ m ) was 0.085 μM. The demonstrated modified CPE was also effectively used for the detection of Trp in milk with percentage recovery of 98 %–105.2 %. Furthermore, the modified CPE exhibited good repeatability, reproducibility and appropriate selectivity.
研究领域:
分析化学
·
生物化学
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 12
·127509
·
IF 4.386
Rui Kuang,Ning Deng,Fuying Dong,Yongling Ding,Xuan Kuang
Electrochemical enantiorecognition of Tryptophan (Trp) isomers using Cys@In2S3/GCE prepared by two steps of sulfidation and chiralization from MIL-68(In) is reported. The Cys@In2S3/GCE electrode shows highly selective, sensitive and quantitative analysis towards Trp enantiomers. This proposed chiral sensors could be considered for practical applications in the field of Trp related medical recognition.
研究领域:
生物化学
·
分析化学
·
材料科学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Jinqiu Li,Ning Du,Ruifang Guan,Songfang Zhao
Chiral recognition of amino acid enantiomers is critical in enhancing drug efficacy, detecting disease markers, and understanding physiological processes. Enantioselective fluorescent identification has gained attention among researchers due to its nontoxicity, easy synthesis, and biocompatibility. In this work, chiral fluorescent carbon dots (CCDs) were produced through a hydrothermal reaction followed by chiral modification. The fluorescent probe, Fe3+-CCDs (F-CCDs), was constructed by complexing Fe3+ with CCDs to differentiate between the enantiomers of tryptophan (Trp) and determine ascorbic acid (AA) through an “on–off–on” response. It is worth noting that l-Trp can greatly enhance the fluorescence of F-CCDs with a blue shift, whereas d-Trp does not have any effect on the fluorescence of F-CCDs. F-CCDs showed a low limit of detection (LOD) for l-Trp and l-AA, with an LOD of 3.98 and 6.28 μM, respectively. The chiral recognition mechanism of tryptophan enantiomers using F-CCDs was proposed based on the interaction force between the enantiomers and F-CCDs, as confirmed by UV–vis absorption spectroscopy and density functional theory calculations. The determination of l-AA by F-CCDs was also confirmed through the binding of l-AA to Fe3+ to release CCDs, as seen in UV–vis absorption spectra and time-resolved fluorescence decays. In addition, AND and OR gates were constructed based on the different responses of CCDs to Fe3+ and Fe3+-CCDs to l-Trp/d-Trp, demonstrating the significance of molecular-level logic gates in drug detection and clinical diagnosis.
研究领域:
生物化学
·
医学诊断
·
药物研发
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DOI
高影响因子
OPTICS LETTERS
·
2024
·Vol. 49
·期 5
·1105-1108
·
IF 3.1
Ting Wu,Ting Wu,Ting Wu,Jiuling Liao,Jiuling Liao,Feng Xiang,Feng Xiang,Jia Yu,Jia Yu,Yinwen Huo,Yinwen Huo,Yufeng Gao,Yufeng Gao,Yufeng Gao,Hui Li,Hui Li,Hui Li,Wei Zheng,Wei Zheng,Wei Zheng
Compared to intensity detection, fluorescence lifetime has the advantage of being unaffected by variations in excitation intensity, fluorophore concentration, or attenuation due to biological absorption and scattering. In this Letter, to the best of our knowledge, we present the use of the two-photon excitation autofluorescence lifetime imaging of tryptophan (TRP) to probe cell metabolism for the first time. Tests of pure chemical samples showed that the fluorescence lifetime of TRP was highly sensitive to changes in molecular conformation and the environment. In in vitro cell experiments, we successfully utilized the fluorescence lifetime of TRP to distinguish tumor cells from healthy cells, track the therapeutic effect of the tumor immunotherapy drug 1-MT for HeLa cells, and monitor cells in response to carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced cell apoptosis. These results reveal that the two-photon excitation autofluorescence lifetime of TRP could be a sensitive natural probe of cell metabolism in living cells.
研究领域:
生物物理学
·
医学影像学
·
细胞生物学
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DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Yue Sun,Congcong Huang,Chenglong Ma,Chuanqi Zhao,Mengmeng Liu,Zitong Zhu,Yanjie Zhang,Jinsong Ren,Xiaogang Qu
Bioorthogonal chemistry offers a promising approach for advancing chemoimmunotherapy, yet two critical challenges remain: (1) achieving deep tumor penetration of catalysts while ensuring precise tumor-confined prodrug activation, and (2) reversing metabolic immunosuppression to potentiate immunotherapy efficacy. To tackle these issues, here we fabricate a bioorthogonal probiotic nanosystem (NP@ZIF-8@Apt-Lr) by engineering prodrug catalysts and an indoleamine 2,3-dioxygenase (IDO) inhibitor onto AS1411 aptamer-modified Lactobacillus reuteri (Lr). AS1411-guided recognition and GSH-responsive prodrug decaging provide a double guarantee for tumor-selective drug activation, enabling localized tumor killing and further immunogenic cell death (ICD). Also, the inherent tumor-homing properties of Lr endow the nanosystem with the ability of penetrating deep tissue. More crucially, the released IDO inhibitor blocks the immunosuppressive kynurenine pathway of tryptophan metabolism, while Lr redirects tryptophan metabolism toward the immunostimulatory indole-3-aldehyde pathway through host-microbial crosstalk. Upon treatment, NP@ZIF-8@Apt-Lr overcomes immune tolerance and stimulates T lymphocyte infiltration into tumors. Furthermore, it significantly enhances the efficacy of chemoimmunotherapy by suppressing bilateral tumor development and inducing an immune memory response. This work presents a new strategy for enhancing bioorthogonal chemoimmunotherapy through precise prodrug activation and probiotic-mediated metabolic reprogramming by host-microbial crosstalk.
研究领域:
癌症免疫治疗
·
纳米医学
·
微生物组研究
·
代谢工程
·
生物正交化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
BingBing Wang,Jian-Zhong Xu,Shuai Liu,Zhi-Ming Rao,Wei-Guo Zhang
L-Tryptophan hydroxylation catalyzed by tryptophan hydroxylase (TPH) presents a promising method for synthesizing 5-hydroxytryptophan (5-HTP), yet the limited activity of wild-type human TPH2 restricts its application. A high-activity mutant, MT10 (H318E/H323E), was developed through semi-rational active site saturation testing (CAST) of wild-type TPH2, exhibiting a 2.85-fold increase in k cat / K m over the wild type, thus enhancing catalytic efficiency . Two biotransformation systems were developed, including an in vitro one-pot system and a Whole-Cell Catalysis System (WCCS). In the WCCS, MT10 achieved a conversion rate of only 31.5 % within 32 h. In the one-pot reaction, MT10 converted 50 mM L-tryptophan to 44.5 mM 5-HTP within 8 h, achieving an 89 % conversion rate, outperforming the M1 (NΔ143/CΔ26) variant. Molecular dynamics simulations indicated enhanced interactions of MT10 with the substrate, suggesting improved binding affinity and system stability. This study offers an effective approach for the efficient production of 5-HTP.
研究领域:
生物化学
·
分子生物学
·
合成生物学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2025
·
IF 4.6
Shen Zhang,Zhuo Wang,Tianyu Miao
In terms of the superior performance of gold nanoclusters (Au NCs) and the ubiquitous tryptophan in higher plants, tryptophan stabilized gold nanoclusters (Try@Au NCs) were synthesized through chemical reduction method. The uniformly dispersed Au NCs emitted blue fluorescence at 448 nm when the excitation wavelength was located at 368 nm. On the basis of inner filter effect, Try@Au NCs was used as a turn-off fluorescence nanoprobe for simple and quick detection of alizarin. The water-soluble Try@Au NCs displayed excellent stability under various conditions which was beneficial for practical application. This as-prepared fluorescence nanosensor displayed noticeable sensitivity and selectivity toward alizarin measurement with a detection linear range of 0.5–100 μM and detection limit of 0.092 μM. The satisfactory results of recovery assay stated that this as-developed nanosensor was great promising for alizarin detection in real samples.
研究领域:
分析化学
·
纳米技术
·
生物传感
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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）