MICROCHEMICAL JOURNAL
·
2026
·
IF 5.2
Pengfei Xu,Kang Cheng,Changling Yan,Gongke Wang
A D-His-ZIF-8@AgNPs composite was developed to enhance the conductivity of chiral MOFs via ligand exchange and AgNP loading. • Material characterization confirmed the successful structure and the role of AgNPs in improving conductivity and active sites. • The sensor showed clear discrimination between L-Trp and D-Trp with an efficiency of 2.17, low detection limits, good linearity and repeatability. • Recovery tests in human serum and urine demonstrated high accuracy (94.3%–109%) and low RSD (<5%), indicating strong practicality. Chiral metal–organic frameworks (CMOFs) have emerged as a significant research focus in the field of electrochemical sensing. This is attributable to their finely tunable architectures and inherent chiral microenvironments. However, they still face challenges such as inadequate electrical conductivity and limited enantioselective recognition efficiency. Therefore, this study developed a novel electrochemical chiral sensor based on a composite material of chiral metal–organic frameworks and silver nanoparticles. This sensor is used for the highly selective recognition of tryptophan enantiomers. A chiral material, D-His-ZIF-8, was successfully synthesized by introducing D-histidine (D-His) into the ZIF-8 framework via a ligand exchange method. Subsequently, silver nanoparticles (AgNPs) were loaded to obtain the D-His-ZIF-8@AgNPs composite. Electrochemical characterization demonstrated that incorporating AgNPs markedly improved the composite's electrical conductivity and electrochemically active surface area, while also substantially reducing its charge-transfer resistance. Under optimized conditions, the fabricated sensor showed clearly differentiated electrochemical signals toward L-tryptophan and D-tryptophan. The recognition efficiency (I L /I D ) reached 2.17, indicating a stronger affinity for the L-enantiomer. The platform also exhibited excellent enantioselectivity and reliable anti-interference performance. This study provides a novel material design strategy for high-performance chiral recognition sensors and shows promising potential for biomedical detection applications. Download: Download high-res image (107KB) Download: Download full-size image
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Nature Microbiology
·
2023
·Vol. 8
·期 5
·919-933
·
IF 28.3
Han Ji-Xuan,Tao Zhi-Hang,Wang Ji-Lin,Zhang Lu,Yu Chen-Yang,Kang Zi-Ran,Xie Yuanhong,Li Jialu,Lu Shiyuan,Cui Yun,Xu Jia,Zhao Enhao,Wang Ming,Chen Jinxian,Wang Zheng,Liu Qiang,Chen Hui-Min,Su Wenyu,Zou Tian-Hui,Zhou Cheng-Bei,Hong Jie,Chen Haoyan,Xiong Hua,Chen Ying-Xuan,Fang Jing-Yuan
Epidemiological studies have indicated an association between statin use and reduced incidence of colorectal cancer (CRC), and work in preclinical models has demonstrated a potential chemopreventive effect. Statins are also associated with reduced dysbiosis in the gut microbiome, yet the role of the gut microbiome in the protective effect of statins in CRC is unclear. Here we validated the chemopreventive role of statins by retrospectively analysing a cohort of patients who underwent colonoscopies. This was confirmed in preclinical models and patient cohorts, and we found that reduced tumour burden was partly due to statin modulation of the gut microbiota. Specifically, the gut commensal Lactobacillus reuteri was increased as a result of increased microbial tryptophan availability in the gut after atorvastatin treatment. Our in vivo studies further revealed that L. reuteri administration suppressed colorectal tumorigenesis via the tryptophan catabolite, indole-3-lactic acid (ILA). ILA exerted anti-tumorigenic effects by downregulating the IL-17 signalling pathway. This microbial metabolite inhibited T helper 17 cell differentiation by targeting the nuclear receptor, RAR-related orphan receptor γt (RORγt). Together, our study provides insights into an anti-cancer mechanism driven by statin use and suggests that interventions with L. reuteri or ILA could complement chemoprevention strategies for CRC.
研究领域:
肿瘤学
·
胃肠病学
·
微生物学
·
药理学
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ACS Applied Nano Materials
·
2026
·Vol. 9
·期 33
·15691-15704
·
IF 5.8
Kozłowski Filip,Agback Peter,Agback Tatiana,Gohil Suresh,Małecka Małgorzata,Wiglusz Rafał Jakub,Lewińska Agnieszka,Witwicki Maciej,Bartkowiak Aleksandra,Yan Yige,Meijer Johan,Seisenbaeva Gulaim A.,Kessler Vadim G.
Tryptophan (Trp)
oxidation is a key biochemical process influencing
plant development and numerous biomedical pathways. Here, we investigate
how manganese doping modulates the catalytic behavior of titanium
dioxide nanoparticles toward selective Trp oxidation. Mn-doped TiO 2 nanoparticles containing 5%, 10%, and 20% Mn were systematically
examined, while structurally related metal oxides (pristine TiO 2 , MnO 2 , MnFe 2 O 4 , maghemite
(γ-Fe 2 O 3 ), and industrial Fe 3 O 4 ) were included as reference materials to establish
catalytic benchmarks. Whereas the reference oxides predominantly promoted
nonspecific reactive oxygen species (ROS) generation or exhibited
lower catalytic efficiency, Mn-doped TiO 2 displayed highly
tunable reactivity. Specifically, 5% Mn doping favored broad-spectrum
photocatalytic ROS production, whereas increasing the Mn content to
20% transformed the material from a conventional photocatalyst into
a highly selective nanozyme. The 20% Mn-doped TiO 2 exhibited
superior biomimetic catalytic activity and was therefore subjected
to detailed mechanistic studies. Nuclear magnetic resonance (NMR)
spectroscopy and mass spectrometry (MS) revealed highly selective,
nanozyme-driven Trp oxidation pathways leading to the formation of
auxin-mimicking metabolites. In vivo experiments
using Arabidopsis thaliana demonstrated
that the resulting metabolite cocktail significantly stimulated lateral
root formation, indicating improved nutrient acquisition potential.
Collectively, these findings establish Mn-doped TiO 2 as
a tunable catalytic platform capable of directing amino acid oxidation
toward biologically relevant products and highlight its potential
applications in agriculture and biomedicine.
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BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2020
·Vol. 68
·期 2
·381-389
·
IF 1.638
Dawei You,Yue Feng,Can Wang,Chengtao Sun,Yao Wang,Degang Zhao,Guoyin Kai
Tryptophan decarboxylase (TDC, EC 4.1.1.28) catalyzes tryptophan decarboxylation to form tryptamine through the cofactor pyridoxal-5′-phosphate (PLP), a crucial stage in the production of the terpenoid indole alkaloids like camptothecin (CPT). A new gene encoding TDC was identified from the CPT-producing plant Ophiorrhiza pumila by transcriptome analysis, termed OpTDC2. It contained a 1,536 bp open reading frame that encodes a 511 amino acid protein with a molecular mass of 57.01 kDa and an isoelectric point of 6.39. Multiple sequence alignment and phylogenetic tree analysis showed the closest similarity (85%) with the TDC from Mitragyna speciosa . Moreover, the highest expression of OpTDC2 was observed in the O. pumila root. To achieve high-efficiency expression of OpTDC2 in Escherichia coli , we fused the TF tag onto the N-terminal of the OpTDC2. Optimum enzymatic activity was observed at 45 °C, pH 8 and cofactor concentration of 0.1 mM. The catalytic reaction was strongly inhibited by metal ions of Cu 2+ , Zn 2+ , and Fe 2+ . The l -tryptophan was particularly catalyzed compared with d -tryptophan. Besides, the K m and k cat of the OpTDC2 were 1.08 mM and 0.78 Sec −1 , respectively. The results provided information on new functional OpTDC2 that might be used in synthetic biology for the enhanced biosynthesis of CPT in O. pumila .
研究领域:
植物学
·
生物化学
·
分子遗传学
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2023
·Vol. 39
·期 6
·976-984
·
IF 3.1
Hou Huipeng,Tang Shanshan,Wang Wei,Liu Miao,Liang Axin,Xie Bingteng,Yi Yue,Luo Aiqin
I n this work, an electrochemical chiral sensor of a nanowire-like chiral metal-organic framework/multiwalled carbon nanotube-chitosan/glassy carbon electrode( D -MOF/MWCNTs-CS/GCE) was proposed for the enantiorecognition of L / D -tryptophan( L / D -Trp). The asymmetrical spatial structure of D -MOF provides the feasibility for the enantiorecognition of Trp enantiomers. Moreover, differential pulse voltammetry(DPV) was carried out to be the detection method and the DPV peak potential difference(Δ E p ) between L -Trp and D -Trp was referred as the index of the enantiorecognition performance. Several parameters, such as mass ratios and drop-coated volume of MWCNTs-CS, drop-coated volume and concentration of D -MOF, pH and detection temperature of D -MOF/MWCNTs-CS/GCE were optimized for the largest Δ E p value. And the molecular dynamics(MD) simulation was used to elucidate the enantiorecognition mechanism. Furthermore, the proportions of D -Trp( D -Trp%) in Trp mixtures were detected in a good linear relationship with the DPV peak potentials( E p ), and the proposed electrochemical chiral sensor exhibited good reproducibility, stability and enantiorecognition ability. Additionally, the proposed electrochemical chiral sensor( D -MOF/MWCNTs-CS/GCE) has a good application prospect in the fields of biomedicine, clinical diagnosis, chemical production, pharmaceuticals safety and so on.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2022
·
IF 7.129
Jiabin Hong,Xiaoxun Lu,Jieyu Wang,Mengzhu Jiang,Qian Liu,Juntong Lin,Wenjing Sun,Jing Zhang,Yanwei Shi,Xiaoshan Liu
Epidemiological studies have shown that prenatal triphenyl phosphate (TPhP) exposure is related to abnormal neurobehavior in children. However, the neurodevelopmental toxicity of TPhP in mammals is limited. To study the neurodevelopmental toxicity of TPhP in mammals and investigate the underlying mechanism, we used a mouse intrauterine TPhP exposure model. We measured the inflammatory factors (IL-6, TNFα) and NFκB levels, and tryptophan metabolism in placentae, detected the fetal brain transcriptome, hippocampal neuron development and neurobehavioral in the male offspring. The results showed that the protein level of IL-6, TNFα and NFκB in the placenta of the TPhP treatment group (1, 5 mg/kg) were significantly increased. Change of the protein level of these pro-inflammatory factors in maternal serum or fetal brain was not observed. Expression of genes along tryptophan-serotonin metabolism pathway were significantly decreased. While, the concentration of 5-HT levels in the placenta or fetal brain were significantly increased. Consistent with the increased 5-HT, the Nissl body was reduced in the hippocampus of treatment group. The expression of serotonergic neuron gene markers including Tph2 , Htr1A , Htr2A , Pet1 and Lmx1b in the hippocampus of treatment group was significantly decreased. The neurobehavioral test showed that TPhP decreased center time that represent anxiety-like behavior, and reduced learning and memory in male offspring. Meanwhile, expression of genes along tryptophan-kynurenine metabolism pathway were significantly increased. The result of the transcriptome analysis of fetal brain showed that the differentially expressed genes are mainly involved in the transcription regulation of DNA as a template in the nucleus, and the enriched pathways are mainly signal pathways regulated by axon guidance and neurotrophic factors, dopaminergic and cholinergic synapses, suggest that not only serotonergic neuronal was affected. Overall, this study demonstrates that TPhP has the potential to induce placental inflammatory response in the placenta, disturb placental tryptophan metabolism, compromise the neuronal development and synaptic transmission, and cause abnormal neurobehavior in male offspring.
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Frontiers in Plant Science
·
2022
·
IF 6.627
Qiao Chong,Chen Fei,Liu Zhan,Huang Tianfang,Li Wei,Zhang Guolin,Luo Yinggang
Tryptophan decarboxylases (TDCs) are a group of pyridoxal 5′-phosphate-dependent enzymes involved in the enzymatic conversion of tryptophan into tryptamine, a critical biogenic amine. We herein mined and cloned a TDC-encoding gene, CaTDC3, from camptothecin-producing plant Camptotheca acuminata. The intact CaTDC3 was heterologously overexpressed in Escherichia coli and the recombinant CaTDC3 was purified to homogeneity. High-performance liquid chromatography (HPLC)-diode array detector (DAD) and high resolution mass spectrometry (HRMS) data analyses of the CaTDC3-catalyzed reaction mixture confirmed the catalytically decarboxylative activity of CaTDC3. CaTDC3 shows strict stereoselectivity for L-tryptophan. Homology modeling and molecular docking implied CaTDC3’s recognition of L-tryptophan derivatives and analogs. Substrate scope investigations revealed that the appropriate substituent groups on the indole ring, i.e., hydroxylated and halogenated L-tryptophans, could be recognized by CaTDC3 and the decarboxylation reactions generated the corresponding tryptamines. The Cβ -methyl-L-tryptophans were decarboxylated by CaTDC3 efficiently. 1-Thio-L-tryptophan, the NH group of the indole ring replaced by an S atom, could be decarboxylated by CaTDC3. CaTDC3 catalyzed the decarboxylation of 7-aza-L-tryptophan, an N displacement of the C on the aromatic ring, to afford 7-aza-tryptamine. L-Kynurenine, an L-tryptophan degradation product, could be decarboxylated by CaTDC3. The present works uncover a catalytically promiscuous TDC and the TDC is a versatile decarboxylase in synthetic biology for specialized pharmaceutically important substances.
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CHINESE JOURNAL OF CHEMISTRY
·
2022
·Vol. 40
·期 15
·1821-1830
·
IF 5.56
Xin Lu,Yijun Liu,Nan Qin,Chenxi Du,Yanyu Hu,Yao Chen,Haopeng Sun
Comprehensive Summary The cholinesterases are essential targets implicated in the pathogenesis of Alzheimer's disease (AD). We have identified tryptophan-tetrahydroisoquinoline derivatives as selective micro-nanomolar butyrylcholinesterase (BChE) inhibitors. Molecular docking was applied for the rational design and binding mode analysis. They were defined according to their target inhibitory activity, low cytotoxicity, predicted permeability through the blood-brain barrier (BBB), and in vivo cognitive improvement. Additionally, the preferred compound showed ability to decrease self-induced Aβ 1-42 aggregation and Aβ 1-42 induced SH-SY5Y cell injury. Altogether, these factors indicated their potential as unique lead compounds for AD treatment.
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Microbial Cell Factories
·
2022
·Vol. 21
·期 1
·1-9
·
IF 6.352
Wang Yingying,Chen Xueman,Chen Qiaoyu,Zhou Ning,Wang Xin,Zhang Alei,Chen Kequan,Ouyang Pingkai
Background l-Tryptophan (l-Trp) derivatives such as 5-hydroxytryptophan (5-HTP) and 5-hydroxytryptamine (5-HT), N-Acetyl-5-hydroxytryptamine and melatonin are important molecules with pharmaceutical interest. Among, 5-HT is an inhibitory neurotransmitter with proven benefits for treating the symptoms of depression. At present, 5-HT depends on plant extraction and chemical synthesis, which limits its mass production and causes environmental problems. Therefore, it is necessary to develop an efficient, green and sustainable biosynthesis method to produce 5-HT.Results Here we propose a one-pot production of 5-HT from l-Trp via two enzyme cascades for the first time. First, a chassis cell that can convert l-Trp into 5-HTP was constructed by heterologous expression of tryptophan hydroxylase from Schistosoma mansoni (SmTPH) and an artificial endogenous tetrahydrobiopterin (BH4) module. Then, dopa decarboxylase from Harminia axyridis (HaDDC), which can specifically catalyse 5-HTP to 5-HT, was used for 5-HT production. The cell factory, E. coli BL21(DE3)△tnaA/BH4/HaDDC-SmTPH, which contains SmTPH and HaDDC, was constructed for 5-HT synthesis. The highest concentration of 5-HT reached 414.5 ± 1.6 mg/L (with conversion rate of 25.9 mol%) at the optimal conditions (substrate concentration,2 g/L; induced temperature, 25℃; IPTG concentration, 0.5 mM; catalysis temperature, 30℃; catalysis time, 72 h).Conclusion sThis protocol provided an efficient one-pot method for converting. l-Trp into 5-HT production, which opens up possibilities for the practical biosynthesis of natural 5-HT at an industrial scale.
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ANALYTICA CHIMICA ACTA
·
2013
·
IF 4.387
Lin Zhang,Chunli Xu,Cunwei Liu,Baoxin Li
A simple protocol to distinguish enantiomers is extremely intriguing and useful. In this study, we propose a low-cost, facile, sensitive method for visual chiral recognition of enantimers. It is based on the inherent chirality of gold nanoparticles (AuNPs), and the unmodified AuNPs are used as chiral selector for d - and l -Tryptophan (Trp). In the presence of d -Trp, an appreciable red-to-blue color change of AuNPs solution can be observed, whereas no color change is found in the presence of l -Trp. The method can be used to detect d -Trp in the range of 0.2–10 μM, and the limit of detection is 0.1 μM. The chiral assay described in this work is easily readout with the naked eye or using a UV-vis spectrometer. Furthermore, the AuNPs can selectively adsorb d -Trp, and simple centrifugation can allow the precipitation of d -Trp with AuNPs and leave a net excess of the other enantiomer in solution, thus resulting in enantioseparation. In this method, AuNPs do not need any labeling or modifying with chiral molecules. The method is more attractive because of its high sensitivity, low cost, ready availability and simple manipulation.
研究领域:
分析化学
·
纳米科技
·
生物化学
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ACS Omega
·
2023
·
IF 4.1
Yeabsira Mihret,Getu Sisay,Abebe Diro,Solomon Hailemariam,Shimeles Addisu Kitte
Here, a highly sensitive electrochemical sensor for detection of tryptophan (Trp) using a nitrogen defect graphitic carbon nitride-modified glassy carbon electrode (ND-CN/GCE) was introduced. ND-CN/GCE showed a higher oxidation current for Trp than the graphitic carbon nitride-modified glassy carbon electrode (g-CN/GCE) and bare glassy carbon electrode (BGCE). The synthesized nitrogen defect-rich graphitic carbon nitride (ND-CN) was characterized using X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical impedance spectroscopy and cyclic voltammetry were used to further analyze the electrochemical properties of BGCE, g-CN/GCE, and ND-CN/GCE. The oxidation of Trp at ND-CN/GCE is a diffusion-controlled process at pH 3.0. It was calculated that the transfer coefficient, rate constant, and diffusion coefficient of Trp were 0.53, 2.24 × 103 M–1 s–1, and 8.3 × 10–3 cm2 s–1, respectively, at ND-CN/GCE. Trp was detected using square wave voltammetry, which had a linear range from 0.01 to 40 μM at pH 3.0 and a limit of detection of about 0.0034 μM (3σ/m). Analyzing the presence of Trp in a milk and multivitamin tablet sample with a percentage recovery in the range of 97.0–108% satisfactorily demonstrated the practical usability of the electrochemical sensor. The ND-CN/GCE additionally displays good repeatability and reproducibility and satisfactory selectivity.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Xinyi Zhu,Jie Zhao,Feifei Dai,Weitao Xu,Lixia Chen,Xin Xiao,Zhu Tao,Chao Zhang
Herein we present a simple fluorescence quenching method to selectively recognise and determine L-tryptophan (L-Trp) out of other 19 natural amino acids. Methylpillar[5]arene (MeP5), which is employed as a macrocyclic fluorescent probe, exhibits fluorescence activity in the solution of poor solvents because of aggregation-induced emission (AIE) effect. Fluorescence quenching of MeP5 in the solution of EtOH/CH 2 Cl 2 (98/2, v/v) was observed upon the addition of L-Trp whereas other 19 natural amino acids did not bring about obvious change in fluorescence intensity. 1 H NMR titration, fluorescence spectroscopy, mass spectrometry and theoretical analysis revealed that L-Trp can be encapsulated into the cavity of MeP5 to form a stable 1:1 host–guest inclusion complex which accounts for the quenching characteristics. The proposed procedure in this investigation offers an attractive and promising method for the selective detection of L-Trp in a mixture of natural amino acids.
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