Butyrylcholinesterase is regarded as a promising drug target in advanced Alzheimer's disease. In order to identify highly selective and potent BuChE inhibitors, a 53-membered compound library was constructed via the oxime-based tethering approach based on microscale synthesis. Although A2Q17 and A3Q12 exhibited higher BuChE selectivity versus acetylcholinesterase, the inhibitory activities were unsatisfactory and A3Q12 did not inhibit Abeta1-42 peptide self-induced aggregation. With A2Q17 and A3Q12 as leads, a novel series of tacrine derivatives with nitrogen-containing heterocycles were designed based on conformation restriction strategy. The results demonstrated that 39 (IC50 = 3.49 nM) and 43 (IC50 = 7.44 nM) yielded much improved hBuChE inhibitory activity compared to the lead A3Q12 (IC50 = 63 nM). Besides, the selectivity indexes (SI = AChE IC50 / BChE IC50) of 39 (SI = 33) and 43 (SI = 20) were also higher than A3Q12 (SI = 14). The results of the kinetic study showed that 39 and 43 exhibited a mixed-type inhibition against eqBuChE with respective Ki values of 1.715 nM and 0.781 nM. And 39 and 43 could inhibit Abeta1-42 peptide self-induced aggregation into fibril. X-ray crystallography structures of 39 or 43 complexes with BuChE revealed the molecular basis for their high potency. Thus, 39 and 43 are deserve for further study to develop potential drug candidates for the treatment of Alzheimer's disease.
Title: Engineering a Bacillus subtilis esterase for selective hydrolysis of d, l-menthyl acetate in an organic solvent-free system Qiao J, Yang D, Feng Y, Wei W, Liu X, Zhang Y, Zheng J, Ying X Ref: RSC Adv, 13:10468, 2023 : PubMed
Esterase/lipase-catalyzed selective hydrolysis of d, l-menthyl esters has become one of the promising approaches for producing l-menthol, one of the most important flavoring chemicals with extensive uses. However, the activity and l-enantioselectivity of the biocatalyst are not sufficient for meeting the industrial requirements. Herein, a highly active para-nitrobenzyl esterase from Bacillus subtilis 168 (pnbA-BS) was cloned and then engineered to enhance its l-enantioselectivity. On the basis of the strategy tailoring the steric exclusion effect and structural flexibility of the region adjacent to the substrate, the substitution of Ala400 to Pro caused a remarkable improvement in the E value from 1.0 to 466.6. The variant A400P was purified and further confirmed with strict l-enantioselectivity in the selective hydrolysis of d, l-menthyl acetate, whereas the improved l-enantioselectivity caused decreased activity. To develop an efficient, easy-to-use, and green methodology, organic solvent was omitted and substrate constant feeding was integrated into the whole-cell catalyzed system. During the catalytic process, the selective hydrolysis of 1.0 M d, l-menthyl acetate in 14 h offered a conversion of 48.9%, e.e.(p) value of >99%, and space-time yield of 160.52 g (l d)(-1).
Title: Synthesis of EPA-enriched medium- and long-chain triacylglycerol by lipase-catalyzed transesterification: a novel strategy for clinical nutrition intervention Wang Y, Wei W, Liu R, Chang M, Jin Q, Wang X Ref: J Sci Food Agric, :, 2023 : PubMed
BACKGROUND: Eicosapentaenoic acid (EPA) has been recognized as a promising nutrient to improve the therapeutic efficacy of cancer patients. Nevertheless, there are certain limitations to the application of EPA due to its structural characteristics. To maximize the nutritive value of EPA, a type of medium- and long-chain triacylglycerol (MLCT) enriched with EPA was designed and synthesised via lipase-catalyzed transesterification of medium-chain triglyceride (MCT) and EPA-enriched fish oil (FO). RESULTS: The optimum synthesis conditions for EPA-enriched MLCT were Lipozyme RM as catalyst, substrate mass ratio (MCT/ EPA-enriched FO) 3:1, lipase loading 80 g kg(-1) , reaction temperature 60 degreesC, and reaction time 6 h. The content of MLCT was up to 80.79% after the transesterification reaction and the purification, and the content of MLCT containing EPA accounted for 70.21%. Furthermore, the distribution of EPA at the sn-2 position showed a significant increase in MLCT compared with original substrate, from 18.89% to 26.93%. Further, the in vitro digestion results demonstrated that MLCT had a significantly higher EPA bioaccessibility compared to the original substrate. CONCLUSION: The EPA-enriched MLCT has been developed, which may be a novel strategy for clinical nutrition intervention. This article is protected by copyright. All rights reserved.
There is a significant interest in identifying blood-borne factors that mediate tissue crosstalk and function as molecular effectors of physical activity. Although past studies have focused on an individual molecule or cell type, the organism-wide secretome response to physical activity has not been evaluated. Here, we use a cell-type-specific proteomic approach to generate a 21-cell-type, 10-tissue map of exercise training-regulated secretomes in mice. Our dataset identifies >200 exercise training-regulated cell-type-secreted protein pairs, the majority of which have not been previously reported. Pdgfra-cre-labeled secretomes were the most responsive to exercise training. Finally, we show anti-obesity, anti-diabetic, and exercise performance-enhancing activities for proteoforms of intracellular carboxylesterases whose secretion from the liver is induced by exercise training.
Title: Identification, Characterization, and Computer-Aided Rational Design of a Novel Thermophilic Esterase from Geobacillus subterraneus, and Application in the Synthesis of Cinnamyl Acetate Zhang J, Lin L, Wei W, Wei D Ref: Appl Biochem Biotechnol, :, 2023 : PubMed
Investigation of a novel thermophilic esterase gene from Geobacillus subterraneus DSMZ 13552 indicated a high amino acid sequence similarity of 25.9% to a reported esterase from Geobacillus sp. A strategy that integrated computer-aided rational design tools was developed to select mutation sites. Six mutants were selected from four criteria based on the simulated saturation mutation (including 19 amino acid residues) results. Of these, the mutants Q78Y and G119A were found to retain 87% and 27% activity after incubation at 70 degreesC for 20 min, compared with the 19% activity for the wild type. Subsequently, a double-point mutant (Q78Y/G119A) was obtained and identified with optimal temperature increase from 65 to 70 degreesC and a 41.51% decrease in K(m). The obtained T(1/2) values of 42.2 min (70 degreesC) and 16.9 min (75 degreesC) for Q78Y/G119A showed increases of 340% and 412% compared with that in the wild type. Q78Y/G119A was then employed as a biocatalyst to synthesize cinnamyl acetate, for which the conversion rate reached 99.40% with 0.3 M cinnamyl alcohol at 60 degreesC. The results validated the enhanced enzymatic properties of the mutant and indicated better prospects for industrial application as compared to that in the wild type. This study reported a method by which an enzyme could evolve to achieve enhanced thermostability, thereby increasing its potential for industrial applications, which could also be expanded to other esterases.
Title: A novel pomegranate-inspired bifunctional electrode materials design for acetylcholinesterase biosensor and methanol oxidation reaction Wei W, Tang H, Dong S, Fu Y, Huang T Ref: Bioelectrochemistry, 145:108094, 2022 : PubMed
A pomegranate-inspired bifunctional electrode material based on Ni/NiO nanoparticle embedded in nitrogen-doped, partially graphitized carbon framework (Ni/NiO@NPGC) was designed and prepared for the construction of novel electrochemical biosensor and methanol oxidation reaction (MOR). Profiting from itsspecialstructureandfunction, Ni/NiO@NPGC was employed as a matrix immobilizing acetylcholinesterase (AChE) for methyl parathion (MP) sensor. The developed biosensor was proved to have wide linear range (1.0 x 10(-14)-1.0 x 10(-8) g mL(-1)), low detection limit (3.5 x 10(-15) g mL(-1)), and good stability for the determination of MP in practical samples. In addition, the Ni/NiO@NPGC electrode exhibited high electrocatalytic activity (specific activity 73.1 mA cm(-2)) and durability for the MOR in alkaline medium. The results were mainly attributed to the pomegranate-like architecture structure with pyridinic N and carbon frame of Ni/NiO@NPGC, which ensured the electrochemical activities of all nanoparticles and immobilization of enzyme. In addition, the metal oxide was well dispersed to prevent from self-agglomeration and kept mass transfer paths. The work provides a reference for the development of high-performance bifunctional electrode material for the biosensor and MOR.
A novel alkaloid caulophyine A (1) was isolated from the roots of Caulophyllum robustum Maxim., along with six known alkaloids 2-7. The structure of 1 was elucidated by extensive NMR and high resolution-time-of-flight (HR-TOF)-MS analyses, it is a rare nitrogen containing polycyclic aromatic hydrocarbon. The in vitro bioassays revealed that 2 presented remarkable cytotoxicity against A549 with an IC(50) value of 3.83 microM in comparison with the positive control etoposide (IC(50) = 11.63 microM). Compounds 1 and 2 also displayed weak Acetylcholinesterase (AChE) inhibitory activity with IC(50) values of 123.03 and 80.74 microM respectively.
Title: Functional expression of a novel methanol-stable esterase from Geobacillus subterraneus DSM13552 for biocatalytic synthesis of cinnamyl acetate in a solvent-free system Cai X, Lin L, Shen Y, Wei W, Wei DZ Ref: BMC Biotechnol, 20:36, 2020 : PubMed
BACKGROUND: Esterases are widely distributed in nature and have important applications in medical, industrial and physiological. Recently, the increased demand for flavor esters has prompted the search of catalysts like lipases and esterases. Esterases from thermophiles also show thermal stability at elevated temperatures and have become enzymes of special interest in biotechnological applications. Although most of esterases catalyzed reactions are carried out in toxic and inflammable organic solvents, the solvent-free system owning many advantages such as low cost and easy downstream processing. RESULTS: The gene estGSU753 from Geobacillus subterraneus DSM13552 was cloned, sequenced and overexpressed into Escherichia coli BL21 (DE3). The novel gene has an open reading frame of 753 bp and encodes 250-amino-acid esterase (EstGSU753). The sequence analysis showed that the protein contains a catalytic triad formed by Ser97, Asp196 and His226, and the Ser of the active site is located in the conserved motif Gly95-X-Ser97-X-Gly99 included in most esterases and lipases. The protein catalyzed the hydrolysis of pNP-esters of different acyl chain lengths, and the enzyme specific activity was 70 U/mg with the optimum substrate pNP-caprylate. The optimum pH and temperature of the recombinant enzyme were 8.0 and 60 degrees C respectively. The resulting EstGSU753 showed remarkable stability against methanol. After the incubation at 50% methanol for 9 days, EstGSU753 retained 50% of its original activity. Even incubation at 90% methanol for 35 h, EstGSU753 retained 50% of its original activity. Also, the preliminary study of the transesterification shows the potential value in synthesis of short-chain flavor esters in a solvent-free system, and more than 99% conversion was obtained in 6 h (substrate: cinnamyl alcohol, 1.0 M). CONCLUSIONS: This is the first report of esterase gene cloning from Geobacillus subterraneus with detailed enzymatic properties. This methanol-stable esterase showed potential value in industrial applications especially in the perfume industry.
Title: Enhancing hydrogel-based long-lasting chemiluminescence by a platinum-metal organic framework and its application in array detection of pesticides and d-amino acids Lu Y, Wei M, Wang C, Wei W, Liu Y Ref: Nanoscale, :, 2020 : PubMed
Organophosphorus pesticides (OPs) are harmful to people's health and d-amino acids (d-AAs) in the human body are closely related to various diseases. So, detection of OPs in foods and d-AAs in serum is important for food safety and clinical diagnosis. Herein, a long-lasting chemiluminescence (CL) imaging sensor was constructed for the detection of OPs and d-AAs. The method was based on N-(4-aminobutyl)-N-ethylisoluminol/Co2+/chitosan (ABEI/Co2+/CS) hydrogels, where metal organic framework materials (MOF-Pt) were selected as catalysts to improve the sensitivity greatly. Under the catalysis of acetylcholinesterase (AChE) and choline oxidase (CHO), H2O2 was produced by using acetylcholine chloride (ACh) as a substrate, which was sensitive to the proposed CL system. OPs inhibited the activity of AChE and decreased the production of H2O2, reducing CL intensity. The linear range of the method for chlorpyrifos was 0.5 ng mL-1-1.0 mug mL-1, with a limit of detection (LOD) of 0.21 ng mL-1. Seventeen kinds of OPs can be visually and simultaneously discerned by the CL imager. On the other hand, d-AAs were catalyzed and oxidized by d-alpha-amino oxidase (DAAO) to produce H2O2. Thus, d-Ala in serum was used as a model to be detected by the proposed method. The linear range for d-Ala was 1.0 muM-10 mM, with an LOD of 0.12 muM.
Title: The cross-sectional study of hepatic lipase SNPs and plasma lipid levels Wei W, Hu T, Luo H, Ye Z, Lu F, Wu Y, Ying M Ref: Food Sci Nutr, 8:1162, 2020 : PubMed
By the combination of meta-analysis, the data of the 1,000 Genomes Project Phase 3, and the promoter sequence of hepatic lipase (LIPC), we performed the cross-sectional study to explore the associations of four variants (rs1077835; rs1077834; rs1800588 [C-514T], and rs2070895 [G-250A]) in LIPC promoter with plasma lipid levels. Our results indicate that the first and the next three of the four SNPs are, respectively, reported to be associated with the decreased and increased HDL-c level. Meta-analysis of 87 studies with 101,988 participants indicates that HDL-c level in rs1800588 (C-514T) (pooled mean difference = 0.03, 95%CI (0.03, 0.04), p < .001) and rs2070895 (G-250A) (pooled mean difference = 0.07, 95%CI (0.05, 0.09), p < .001) is higher in allele T or A carriers. Similarly, LDL-c, TC, TG, and BMI levels are generally increased in T or A alleles carriers. We failed to conduct the meta-analysis of rs1077835 and rs1077834 due to the limited previous reports. Data from the 1,000 Genomes indicate that the allele frequencies of the four SNPs in total or subpopulations are almost equal to each other. The paired value r (2) and D' of the four SNPs are larger than 0.8, which indicate the linkage disequilibrium of the four variants. The analysis of LIPC promoter indicate that C-514T and G-250A are, respectively, located in transcriptional factor binding sites of USF1and Pbx1b, which may partly explain the effect of the two SNPs on the decreased LIPC activity in the alleles carriers and the corresponding increased plasma lipids hydrolyzed by LIPC. These results may help us to better understand the different effects of the four SNPs on the plasma lipid levels among subpopulations and offer clues for future clinical treatment of dyslipidemia-related diseases.
Title: Insecticidal activity of triterpenoids and volatile oil from the stems of Tetraena mongolica Wu Z, Wei W, Cheng K, Zheng L, Ma C, Wang Y Ref: Pestic Biochem Physiol, 166:104551, 2020 : PubMed
Tetraena mongolica Maxim is a species of Zygophyllaceae endemic to China. Because few insect pests affect its growth and flowering, we speculated that this plant produces defensive chemicals that are insect repellents or antifeedants. The effects of different fractions from crude stem and leaf extracts on Pieris rapae were examined. The results confirmed that the ethyl acetate (EtOAc) fraction from the stems had insecticidal potential. Five compounds were isolated from the EtOAc fraction: a volatile oil [bis(2-ethylhexyl) benzene-1,2-dicarboxylate (1)], three triterpenoids 2E-3beta-(3,4-dihydroxycinnamoyl)-erythrodiol (2), 2Z-3beta-(3,4-dihydroxycinnamoyl)-erythrodiol (3), and 2E-3beta-(3,4-dihydroxyphenyl)-2-propenoate (4)], and one steroid [beta-sitosterol (5)]. Compounds 1-5 exhibited different degrees of insecticidal activity, including antifeedant and growth-inhibition effects. Compounds 1-5 inhibited the activity of carboxylesterase (CarE) and acetylcholinesterase (AChE) to different degrees. Compound 1 had the strongest antifeedant and growth-inhibition effects, and significantly inhibited the activity of CarE and AChE. Our results indicate that compounds 1-4 are the major bioactive insecticidal constituents of Tetraena mongolica. This work should facilitate the development and application of plant-derived botanical pesticides.
Title: Toxicity comparison of nano-sized and micron-sized microplastics to Goldfish Carassius auratus Larvae Yang H, Xiong H, Mi K, Xue W, Wei W, Zhang Y Ref: J Hazard Mater, 388:122058, 2020 : PubMed
Plastic pollution is one of the most serious environmental issues worldwide. The negative influence of plastics on aquatic organisms has increasingly concerned, especially the influence of microplastic (MPs). In the present study, the toxicology of nano-sized MPs (nMPs) and micron-sized MPs (mMPs) were comparatively studied. Goldfish larvae were exposed to 10, 100 and 1000 mug/L nMPs and mMPs for 1, 3 and 7 days. The enrichment of MPs, body length, heart rate, motor ability, microscopic and ultrastructure of intestine, liver, gill and muscle tissue, as well as the oxidative stress were analyzed. Results showed that both 70 nm and 50 mum MPs were accumulated in the digestive tract of larvae. MPs at high concentrations could induce oxidative stress, destroy intestine, liver and gill tissues, increase heart rate, and inhibit growth and swimming speed of the larvae. The most important finding was that nMPs could enter into the muscle tissue through the epidermis of the larvae. It could cause damage to muscle tissue, destroy nerve fibers, inhibit acetylcholinase (AchE) activity, and show great adverse effects on larval movement than mMPs. In conclusion, both nMPs and mMPs at higher concentrations can cause damage to fish larvae and nMPs are potentially more hazardous.
Title: Immobilization of Lipozyme TL 100L for methyl esterification of soybean oil deodorizer distillate Zheng J, Wei W, Wang S, Li X, Zhang Y, Wang Z Ref: 3 Biotech, 10:51, 2020 : PubMed
An immobilization method for binding cross-linked enzyme aggregates of Lipozyme TL 100L on macroporous resin NKA (CLEA-TLL@NKA) was developed in this study. The esterification activity of CLEA-TLL@NKA reached 6.4 U/mg. The surface structure of immobilized lipase was characterized by scanning electron microscopy. Methyl esterification reaction of soybean oil deodorizer distillate (SODD) was catalyzed by CLEA-TLL@NKA, which the conversion rate reached 98% and its activity retained over 90% after 20 batches of reaction. Compared with the commercial enzyme Lipozyme TLIM, half-life (t 1/2) of CLEA-TLL@NKA increased by 25 times and the catalytic activity increased by approximate 10 times. Thus, CLEA-TLL@NKA had high catalytic activity, good operational stability, and potential industrial application in the field of oil processing.
Title: An OliGreen-responsive fluorescence sensor for sensitive detection of organophosphorus pesticide based on its specific selectivity towards T-Hg(2+)-T DNA structure Zhou X, Wang C, Wu L, Wei W, Liu S Ref: Spectrochim Acta A Mol Biomol Spectrosc, 247:119155, 2020 : PubMed
In this paper, it was found that OliGreen emitted much stronger fluorescence in rigid T-Hg(2+)-T DNA structure than that in the presence of poly T. Thus, an OliGreen-responsive label-free fluorescent sensor was proposed for sensitive detection of organophosphorus pesticides (OPs) by constructing T-Hg(2+)-T DNA structure. OliGreen emits strong fluorescence in T-Hg(2+)-T structures. The rigid DNA structure of T-Hg(2+)-T is prone to be destroyed by thiocholine (TCh) that hydrolyzed by acetylcholinesterase (AChE) because of the high affinity of TCh with Hg(2+). As a result, T-Hg(2+)-T DNA structure broke down and the fluorescence intensity of OliGreen decreased greatly. With the inhibition of AChE by OPs, fluorescence intensity of OliGreen remained strong because of the rigid T-Hg(2+)-T DNA structure. Thus, a "turn-on" fluorescent sensor which avoids synthesis of nanomaterials and complex label procedures is proposed based on the fluorescence intensity of OliGreen. DDVP were detected with a wide linear range from 0.005 to 25.0 ng/mL and the detection limit was 2.9 pg/mL, which is more sensitive than previously reported methods.
BACKGROUND: Rivastigmine is a cholinesterase inhibitor, approved for the treatment of mild-to-moderate dementia of Alzheimer's type. OBJECTIVE: To explore the efficacy and safety of the maximal tolerated dose of rivastigmine capsules in Chinese patients with mild-to-moderate Alzheimer's disease (AD). METHODS: The study was a multicenter, open-label, single-arm, phase IV clinical study in mild-to-moderate drug-naive AD patients treated with rivastigmine capsules. The primary endpoint was the changes in the total scores of Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) from baseline to week 16. Secondary endpoints included changes in the scores of the following assessment scales and safety: Alzheimer's Disease Cooperative Study; Activities of Daily Living; Mini-Mental Status Examination (MMSE); Neuropsychiatry Index (NPI), and Caregiver Burden Inventory. RESULTS: 222 patients were enrolled. Of these, 136 (75.1%) patients received and maintained the effective dose (>/=6 mg/d) of rivastigmine for at least 4 weeks. The ADAS-Cog scale score improved in rivastigmine-treated patients at week 16 compared with baseline (p < 0.001) by 2.0 (95% CI: -3.0 to -1.1) points, which met the pre-defined superiority criteria. NPI-10 and NPI-12 scores improved by 3.6 and 4.0 points at week 16 (p = 0.001, p < 0.001), respectively. A total of 107 patients (59.1%) experienced adverse effects (AEs) during the study; common AEs included nausea (20.5%), vomiting (16.6%), anorexia (7.8%), dizziness (7.7%), and diarrhea (7.2%). CONCLUSION: This was the first phase IV study on rivastigmine in mainland China. The study preliminarily demonstrated that rivastigmine capsules showed good tolerability and efficacy in mild-to-moderate AD patients with the maximal tolerated dose.
Title: Noninvasive Evaluation of Liver Fibrosis Reverse Using Artificial Neural Network Model for Chronic Hepatitis B Patients Wei W, Wu X, Zhou J, Sun Y, Kong Y, Yang X Ref: Comput Math Methods Med, 2019:7239780, 2019 : PubMed
The diagnostic performance of an artificial neural network model for chronic HBV-induced liver fibrosis reverse is not well established. Our research aims to construct an ANN model for estimating noninvasive predictors of fibrosis reverse in chronic HBV patients after regular antiviral therapy. In our study, 141 consecutive patients requiring liver biopsy at baseline and 1.5 years were enrolled. Several serum biomarkers and liver stiffness were measured during antiviral therapy in both reverse and nonreverse groups. Statistically significant variables between two groups were selected to form an input layer of the ANN model. The ROC (receiver-operating characteristic) curve and AUC (area under the curve) were calculated for comparison of effectiveness of the ANN model and logistic regression model in predicting HBV-induced liver fibrosis reverse. The prevalence of fibrosis reverse of HBV patients was about 39% (55/141) after 78-week antiviral therapy. The Ishak scoring system was used to assess fibrosis reverse. Our study manifested that AST (aspartate aminotransferase; importance coefficient = 0.296), PLT (platelet count; IC = 0.159), WBC (white blood cell; IC = 0.142), CHE (cholinesterase; IC = 0.128), LSM (liver stiffness measurement; IC = 0.125), ALT (alanine aminotransferase; IC = 0.110), and gender (IC = 0.041) were the most crucial predictors of reverse. The AUC of the ANN model and logistic model was 0.809 +/- 0.062 and 0.756 +/- 0.059, respectively. In our study, we concluded that the ANN model with variables consisting of AST, PLT, WBC, CHE, LSM, ALT, and gender may be useful in diagnosing liver fibrosis reverse for chronic HBV-induced liver fibrosis patients.
Biotin is an indispensable cofactor in the three domains of life. The unusual virulence factor BioJ of Francisella catalyzes the formation of pimeloyl-ACP, an intermediate in biotin synthesis. Here, we report the 1.58 A crystal structure of BioJ, the enzymatic activity of which is determined with the in vitro reconstituted reaction and biotin bioassay in vivo. Unlike the paradigm BioH, BioJ displays an atypical alpha/beta-hydrolase fold. A structurally conserved catalytic triad (S151, D248, and H278) of BioJ is functionally defined. A proposed model for BioJ catalysis involves two basic residues-rich cavities, of which cavity-1, rather than cavity-2, binds to the ACP moiety of its physiological substrate, pimeloyl-ACP methyl ester. In summary, this finding provides molecular insights into the BioJ gatekeeper of biotin synthesis.
Title: Ratiometric fluorescence sensor for organophosphorus pesticide detection based on opposite responses of two fluorescence reagents to MnO2 nanosheets Yao T, Liu A, Liu Y, Wei M, Wei W, Liu S Ref: Biosensors & Bioelectronics, 145:111705, 2019 : PubMed
The detection of organophosphorus pesticides (OPs) has received considerable attention for their great harm to human beings. Herein, a novel ratiometric fluorescence biosensor was constructed for the determination of OPs by using Scopoletin (SC) and Amplex Red (AR) as probe pairs that have opposite responses to MnO2 nanosheets (MnO2 NS). MnO2 NS possess peroxidase-like catalytic activity, which could quench the fluorescence of SC as well as enhance the fluorescence of the non-fluorescent substance AR by oxidation. In the absence of OPs, acetylcholinesterase (AChE) hydrolyzed acetylcholine chloride (ATCh) into choline (TCh) and acetate. TCh led the decomposition of MnO2 NS to manganese ions (Mn(2+)), increasing signal of SC and decreasing signal of AR. In the presence of OPs, the activity of AChE was inhibited and the decomposition of MnO2 NS was hindered, therefore the fluorescence intensity of SC was weak and the fluorescence intensity of AR had an obvious increase. Moreover, under the optimal conditions, the ratio of fluorescence intensity response recorded on the AR/SC increases with increasing the concentration of DDVP. The method has wider linear range of 5.0pg/mL approximately 500ng/mL with a detection limit of 1.6pg/mL, which is superior to previously reported methods. This strategy has also been applied to a visual observation based on the color change of the solution under UV light.
Title: Three MOF-Templated Carbon Nanocomposites for Potential Platforms of Enzyme Immobilization with Improved Electrochemical Performance Dong S, Peng L, Wei W, Huang T Ref: ACS Appl Mater Interfaces, 10:14665, 2018 : PubMed
An efficient and facile metal-organic framework (MOF)-template strategy for preparing carbon nanocomposites has been developed. First of all, a series of metal ions, including Fe(3+), Zr(4+), and La(3+), were respectively connected with 2-aminoterephthalate (H2ATA) to form three metal-organic frameworks (MOFs) and then three novel MOF-derived materials were obtained by annealing them at 550 degrees C under N2 atmosphere. The morphologies and microstructure results showed that they still retained the original structure of MOFs and formed carbon-supported metal oxide hybrid nanomaterials. Interestingly, it was found that La-MOF-NH2 and its derived materials were first reported, which had wool-ball-like structure formed by many streaky-shaped particles intertwining each other. Furthermore, these MOF-derived materials were all successfully used as effective immobilization matrixes of acetylcholinesterase (AChE) to construct biosensors for the detection of methyl parathion. Especially, [La-MOF-NH2]N2 with wool-ball-like structure not only provided more active sites of multicontents to increase AChE immobilization amount but also facilitated the accessibility of electron transfer and shorten their diffusion length on the surface of electrode. Under optimal conditions, the biosensor based on [La-MOF-NH2]N2 displayed the widest linear range of 1.0 x 10(-13)-5.0 x 10(-9) g mL(-1) and the lowest detection limit of 5.8 x 10(-14) g mL(-1) in three biosensors. This study illustrates the feasibility and the potential of a series of MOF-derived materials for biosensors with improved electrochemical performance.
Neurodegenerative diseases are conventionally demarcated as disorders with selective loss of neurons. Conventional as well as newer molecules have been tested but they offer just symptomatic advantages along with abundant side effects. The discovery of more compelling molecules that can halt the pathology of these diseases will be considered as a miracle of present time. Several synthetic compounds are available but they may cause several other health issues. Therefore, natural molecules from the plants and other sources are being discovered to replace available medicines. In conventional medicational therapies, several plants have been reported to bestow remedial effects. Phytochemicals from medicinal plants can provide a better and safer alternative to synthetic molecules. Many phytochemicals have been identified that cure the human body from a number of diseases. The present article reviews the potential efficacy of plant-derived alkaloids, which possess potential therapeutic effects against several NDDs including Alzheimer's disease (AD), Huntington disease (HD), Parkinson's disease (PD), Epilepsy, Schizophrenia, and stroke. Alkaloids include isoquinoline, indole, pyrroloindole, oxindole, piperidine, pyridine, aporphine, vinca, beta-carboline, methylxanthene, lycopodium, and erythrine byproducts. Alkaloids constitute positive roles in ameliorating pathophysiology of these illnesses by functioning as muscarinic and adenosine receptors agonists, anti-oxidant, anti-amyloid and MAO inhibitors, acetylcholinestrase and butyrylcholinesterase inhibitor, inhibitor of alpha-synuclein aggregation, dopaminergic and nicotine agonist, and NMDA antagonist.
Carboxylesterase and UDP-glucuronosyltransferases mediated metabolism of irinotecan (CPT-11) has long been proposed to be responsible for its anti-tumor activity and toxicity, like delayed-onset diarrhea. However, recent studies failed to gain more comprehensive in vivo and in vitro pharmacokinetic profiles of irinotecan. Herein, we choose rat plasma, human liver microsomes and immortalized HepG2 cell as experimental subjects to describes an sensitive and versatile UHPLC-MS/MS method for simultaneously quantify CPT-11 and its metabolites, including SN-38 and SN-38G. Meanwhile, we have adopted the method to investigate the pharmacokinetic or metabolism behavior of CPT-11 in the above biological samples. Calibration curves for all bio-matrices showed desirable linearity (r(2) >0.99). The intra-day and inter-day precision (RSD, %) were within 15 % and the excellent accuracy (RE, %) was between 2.96% and 14.12%. In addition, the specificity, matrix effect and extraction recovery were all meet the requirements of biological sample analysis. We have successfully applied this method to investigating pharmacokinetic of irinotecan in different biological samples, which mediated by carboxylesterase and UDP-glucuronosyltransferases. And this method could be emplyed in monitoring the metabolic status and clinical efficacy of irinotecan in the future.
The objective of the present study was to explore the association between muscarinic cholinergic signaling and urothelial bladder tumors. Possible associations among overactive bladder (OAB) symptoms and bladder tumors were retrospectively investigated using a multicenter Chinese database with prospectively collected data since 2010. Firstly, it was demonstrated that OAB symptoms, such as urgency, were more severe in patients with invasive bladder cancer and were associated with a reduced prognosis. Following this, muscarinic cholinergic receptor 3 (M3R) expression in urothelium was determined to be lower in invasive cancer tissue than in adjacent non-cancerous tissue, yet M3R upregulation was associated with a reduced progression free survival (PFS) time. Additionally, it was also demonstrated that muscarinic cholinergic receptor 2 (M2R) was upregulated in the sub-urothelium, and this was also associated with a reduced PFS time. Furthermore, it was determined that cholinesterase and acetylcholinesterase were lower in invasive cancer than in non-invasive cancer. In conclusion, the results indicated that M3R expression was downregulated in invasive bladder cancer, which may have a role as a protective anti-oncogene, in contrast to its oncogenic role in numerous other cancer types. Therefore, muscarinic cholinergic signaling may be a novel therapeutic target for treating bladder cancer.
Title: Autotransporter domain-dependent enzymatic analysis of a novel extremely thermostable carboxylesterase with high biodegradability towards pyrethroid pesticides Cai X, Wang W, Lin L, He D, Huang G, Shen Y, Wei W, Wei D Ref: Sci Rep, 7:3461, 2017 : PubMed
The EstPS1 gene, which encodes a novel carboxylesterase of Pseudomonas synxantha PS1 isolated from oil well-produced water, was cloned and sequenced. EstPS1 has an open reading frame of 1923 bp and encodes the 640-amino acid carboxylesterase (EstPS1), which contains an autotransporter (AT) domain (357-640 amino acids). Homology analysis revealed that EstPS1 shared the highest identity (88%) with EstA from Pseudomonas fluorescens A506 (NCBI database) and belonged to the carboxylesterase family (EC 3.1.1.1). The optimum pH and temperature of recombinant EstPS1 were found to be 8.0 and 60 degrees C, respectively. EstPS1 showed high thermostability, and the half-lives (T1/2 thermal inactivation) at 60, 70, 80, 90, and 100 degrees C were 14 h, 2 h, 31 min, 10 min, and 1 min, respectively. To understand the role of the AT domain in carboxylesterase, AT domain-truncated carboxylesterase (EstPS1DeltaAT) was generated. EstPS1DeltaAT showed a clearly decreased secretion rate, owing to the AT domain strongly improved secretory expression in the heterogeneous system. EstPS1 degraded various pyrethroid pesticides, and hydrolysis efficiencies were dependent on the pyrethroid molecular structure. EstPS1 degraded all the tested pyrethroid pesticides and hydrolysed the p-nitrophenyl esters of medium-short-chain fatty acids, indicating that EstPS1 is an esterase with broad specificity.
Title: Synthesis of reticulated hollow spheres structure NiCo2S4 and its application in organophosphate pesticides biosensor Peng L, Dong S, Wei W, Yuan X, Huang T Ref: Biosensors & Bioelectronics, 92:563, 2017 : PubMed
Electrode materials play a key role in the development of electrochemical sensors, particularly enzyme-based biosensors. Here, a novel NiCo2S4 with reticulated hollow spheres assembled from rod-like structures was prepared by a one-pot solvothermal method and its formation mechanism was discussed. Moreover, comparison of NiCo2S4 materials from different experiment conditions as biosensors was investigated by electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV), and the best one that was reticulated hollow spheres assembled from rod-like structures NiCo2S4 has been successfully employed as a matrix of AChE immobilization for the special structure, superior conductivity and rich reaction active sites. When using common two kinds of organophosphate pesticides (OPs) as model analyte, the biosensors demonstrated a wide linear range of 1.0x10-12-1.0x10-8gmL-1 with the detection limit of 4.2x10-13gmL-1 for methyl parathion, and 1.0x10-13-1.0x10-10gmL-1 with the detection limit of 3.5x10-14gmL-1 for paraoxon, respectively. The proposed biosensors exhibited many advantages such as acceptable stability and low cost, providing a promising tool for analysis of OPs.
Title: NDRG1 overexpression promotes the progression of esophageal squamous cell carcinoma through modulating Wnt signaling pathway Ai R, Sun Y, Guo Z, Wei W, Zhou L, Liu F, Hendricks DT, Xu Y, Zhao X Ref: Cancer Biol Ther, 17:943, 2016 : PubMed
N-myc down-regulated gene 1 (NDRG1) has been shown to regulate tumor growth and metastasis in various malignant tumors and also to be dysregulated in esophageal squamous cell carcinoma (ESCC). Here, we show that NDRG1 overexpression (91.9%, 79/86) in ESCC tumor tissues is associated with poor overall survival of esophageal cancer patients. When placed in stable transfectants of the KYSE 30 ESCC cell line generated by lentiviral transduction with the ectopic overexpression of NDRG1, the expression of transducin-like enhancer of Split 2 (TLE2) was decreased sharply, however beta-catenin was increased. Mechanistically, NDRG1 physically associates with TLE2 and beta-catenin to affect the Wnt pathway. RNA interference and TLE2 overexpression studies demonstrate that NDRG1 fails to active Wnt pathway compared with isogenic wild-type controls. Strikingly, NDRG1 overexpression induces the epithelial mesenchymal transition (EMT) through activating the Wnt signaling pathway in ESCC cells, decreased the expression of E-cadherin and enhanced the expression of Snail. Our study elucidates a mechanism of NDRG1-regulated Wnt pathway activation and EMT via affecting TLE2 and beta-catenin expression in esophageal cancer cells. This indicates a pro-oncogenic role for NDRG1 in esophageal cancer cells whereby it modulates tumor progression.
Title: NDRG1 promotes growth of hepatocellular carcinoma cells by directly interacting with GSK-3beta and Nur77 to prevent beta-catenin degradation Lu WJ, Chua MS, Wei W, So SK Ref: Oncotarget, 6:29847, 2015 : PubMed
The N-myc downstream regulated gene 1 (NDRG1) is significantly associated with advanced tumor stages and poor survival of hepatocellular carcinoma (HCC), thereby implicating it as a potential target for HCC treatment. We aim to further understand its biological roles in hepatocarcinogenesis, as a means to exploit it for therapeutic purposes. By screening using the ProtoArray(R) Human Protein Microarrays, we identified glycogen synthase kinase 3beta (GSK-3beta) and the orphan nuclear receptor (Nur77) as potential interaction partners of NDRG1. These interactions were confirmed in HCC cell lines in vitro by co-immunoprecipitation; and co-localizations of NDRG1 with GSK-3beta and Nur77 were observed by immunofluorescence staining. Additionally, high levels of NDRG1 competitively bind to GSK-3beta and Nur77 to allow beta-catenin to escape degradation, with consequent elevated levels of downstream oncogenic genes. In vivo, we consistently observed that NDRG1 suppression in HCC xenografts decreased beta-catenin levels and its downstream target Cyclin D1, with concomitant tumor growth inhibition. Clinically, the over-expression of NDRG1 in HCC patient samples is positively correlated with GSK-3beta-9ser (| R | = 0.28, p = 0.01), Nur77 (| R | = 0.42, p < 0.001), and beta-catenin (| R |= 0.32, p = 0.003) expressions. In conclusion, we identified GSK-3beta and Nur77 as novel interaction partners of NDRG1. These protein-protein interactions regulate the turnover of beta-catenin and subsequent downstream signaling mediated by beta-catenin in HCC cells, and provides potential targets for future therapeutic interventions.
Title: Functional expression of a novel alkaline-adapted lipase of Bacillus amyloliquefaciens from stinky tofu brine and development of immobilized enzyme for biodiesel production Cai X, Ma J, Wei DZ, Lin JP, Wei W Ref: Antonie Van Leeuwenhoek, 106:1049, 2014 : PubMed
Using enrichment procedures, a lipolytic strain was isolated from a stinky tofu brine and was identified as Bacillus amyloliquefaciens (named B. amyloliquefaciens Nsic-8) by morphological, physiological, biochemical tests and 16S rDNA sequence analysis. Meanwhile, the key enzyme gene (named lip BA) involved in ester metabolism was obtained from Nsic-8 with the assistance of homology analysis. The novel gene has an open reading frame of 645 bp, and encodes a 214-amino-acid lipase (LipBA). The deduced amino acid sequence shows the highest identity with the lipase from B. amyloliquefaciens IT-45 (NCBI database) and belongs to the family of triacylglycerol lipase (EC 3.1.1.3). The lipase gene was expressed in Escherichia coli BL21(DE3) using plasmid pET-28a. The enzyme activity and specific activity were 250 +/- 16 U/ml and 1750 +/- 153 U/mg, respectively. The optimum pH and temperature of the recombinant enzyme were 9.0 and 40 degrees C respectively. LipBA showed much higher stability under alkaline conditions and was stable at pH 7.0-11.0. The Km and Vmax values of purified LipBA using 4-nitrophenyl palmitate as the substrate were 1.04 +/- 0.06 mM and 119.05 +/- 7.16 mumol/(ml min), respectively. After purification, recombinant lipase was immobilized with the optimal conditions (immobilization time 3 h at 30 degrees C, with 92 % enzyme recovery) and the immobilized enzyme was applied in biodiesel production. This is the first report of the lipase activity and lipase gene obtained from B. amyloliquefaciens (including wild strain and recombinant strain) and the recombinant LipBA with the detailed enzymatic properties. Also the preliminary study of the transesterification shows the potential value in biodiesel production applications.
Chemical study of the ethyl acetate extract of the plant endophytic fungus Cladosporium sp. (strain no. IFB3lp-2) yielded three new polyketides (1-3), together with nine known compounds. All of the structures were elucidated on the basis of spectroscopic methods. The isolated compounds were screened for their cytotoxic, antiviral, and acetyl cholinesterase inhibitory activities. Regretfully, no compounds showed any significant activity in these assays.
N-myc downstream regulated gene 1 (NDRG1/Cap43/Drg-1) has previously been shown to be dysregulated in esophageal squamous cell carcinoma (ESCC). In this study, we investigated the role of NDRG1 in the neoplastic progression of ESCC using ectopic gain-of-function and loss-of-function approaches. Stable transfectants of the KYSE30 ESCC cell line with altered NDRG1 levels were generated by lentiviral transduction. Although no measurable effects on in vitro cell proliferation were observed with altered NDRG1 expression, the ectopic overexpression of NDRG1 was positively linked to recognized markers of metastasis, angiogenesis and apoptotic evasion. Accordingly, in the nude mouse xenograft model system, NDRG1 overexpression promoted the in vivo growth of KYSE30 derived xenografts, which could be attributed to the reduced apoptotic and enhanced angiogenic activities associated with this gene. These processes were mediated in part by increased NFkappaB activity in NDRG1 overexpressing cells. Nevertheless, no significant phenotypic changes were observed in response to NDRG1 knock-down, suggesting that this gene might not be essential for the neoplastic progression of ESCC. Taken together, our results suggest that NDRG1 may play positive but dispensable roles in the progression of esophageal squamous cell carcinoma.
Bioassay-guided investigation of the stem bark of Hopea chinensis led to the isolation of two new polyphenols, hopeachinols C(1) and D(2), together with ten known compounds (3-12). Compounds 1 and 2 were determined by extensive analysis of spectroscopic data and computational methods. All of these phytochemicals were tested for acetylcholinesterase inhibitory activity, and five resveratrol-derived compounds (1 and 7-10) exhibited significant activity with their IC(5)(0) values ranging from 4.81 to 11.71 microM.
OBJECTIVE: To study the association of PAF-acetyl hydrolase (PAFAH) activity with inflammation, oxidative stress, and atherosclerosis in hypercholesterolemic swine. METHODS AND RESULTS: Cholesterol-rich diet feeding of miniature pigs was associated with an increase in PAFAH activity and an increase of the PAFAH to PON1 ratio. PLA2G7 RNA (coding for PAFAH) expression was increased in blood monocytes and plaque macrophages. Increased PAFAH activity was associated with higher plasma lysophosphatidylcholine and correlated with oxidized LDL. In THP1 monocytes and macrophages and in human blood-derived macrophages, oxidized LDL induced PLA2G7 RNA expression. Atherogenic diet feeding induced the accumulation of macrophages and oxidized LDL in the arterial wall leading to atherosclerosis. PAFAH activity correlated positively with plaque size and TNFalpha expression in plaque macrophages. CONCLUSIONS: We demonstrated that an increase in PAFAH activity was associated with increased levels of lysophosphatidylcholine, oxidized LDL, and inflammation, resulting in accelerated atherosclerosis in hypercholesterolemic minipigs. The significant correlation between PLA2G7 RNA expression in plaque macrophages and plasma PAFAH activity suggests that the latter is a consequence, rather than a cause of macrophage accumulation. Our cell experiments suggest that oxidized LDL can induce PAFAH, resulting in accumulation of lysophosphatidylcholine that increases the inflammatory action of oxidized LDL.
Title: Interactions of Lycopodium alkaloids with acetylcholinesterase investigated by 1H NMR relaxation rate Li Y, Yin G, Wei W, Wang H, Jiang S, Zhu D, Du W Ref: Biophysical Chemistry, 129:212, 2007 : PubMed
In order to further understand the interaction processes between the Lycopodium alkaloids and acetylcholinesterase, the binding properties of N-acetyl huperzine A (1), huperzine B (2) and huperzine F (3) with Torpediniforms Nacline acetylcholinesterase (TnAchE) were investigated by 1H NMR methods. The nonselective, selective and double-selective spin-lattice relaxation rates were acquired in the absence and presence of TnAchE at a ratio of [ligand]/[protein]=1:0.005. The selective relaxation rates show protons of 1-3 have dipole-dipole interaction with protons of TnAchE at the binding interface. The molecular rotational correlation time of bound ligands was calculated by double-selective relaxation rate at 298 K, which showed that 1-3 had high affinity with the protein. The results indicate that investigation of 1H NMR relaxation data is a useful method to locate the new Lycopodium alkaloids as AchE inhibitors.
We sequenced the genome of Saccharomyces cerevisiae strain YJM789, which was derived from a yeast isolated from the lung of an AIDS patient with pneumonia. The strain is used for studies of fungal infections and quantitative genetics because of its extensive phenotypic differences to the laboratory reference strain, including growth at high temperature and deadly virulence in mouse models. Here we show that the approximately 12-Mb genome of YJM789 contains approximately 60,000 SNPs and approximately 6,000 indels with respect to the reference S288c genome, leading to protein polymorphisms with a few known cases of phenotypic changes. Several ORFs are found to be unique to YJM789, some of which might have been acquired through horizontal transfer. Localized regions of high polymorphism density are scattered over the genome, in some cases spanning multiple ORFs and in others concentrated within single genes. The sequence of YJM789 contains clues to pathogenicity and spurs the development of more powerful approaches to dissecting the genetic basis of complex hereditary traits.
Title: Pharmacological characterization of performance on a concurrent lever pressing/feeding choice procedure: effects of dopamine antagonist, cholinomimetic, sedative and stimulant drugs Cousins MS, Wei W, Salamone JD Ref: Psychopharmacology (Berl), 116:529, 1994 : PubMed
This experiment was undertaken to provide a pharmacological characterization of performance on a task involving food-related instrumental and consummatory behavior. Rats were tested in an operant chamber in which there was a choice between pressing a lever to receive a preferred food (Bioserve pellets) or approaching and consuming a less-preferred food (Lab Chow). The lever pressing schedule was a fixed ratio 5 (FR5). Rats usually pressed the lever at high rates to obtain the preferred food, and typically ate little of the lab chow even though it was freely available in the chamber concurrently with the lever pressing schedule. Previous work has shown that injection of dopamine (DA) antagonists, or depletion of DA in the nucleus accumbens, caused a substantial shift in behavior such that lever pressing was reduced but chow consumption increased. In the present study it was shown that the DA antagonist haloperidol decreased lever pressing and increased chow consumption at doses of 0.1 and 0.15 mg/kg. The D1 antagonist SCH 23390 (0.05, 0.1 and 0.15 mg/kg) and the non-selective DA antagonist cis-flupenthixol (0.3 and 0.45 mg/kg) decreased lever pressing and produced substantial increases in chow consumption. The D2 antagonist sulpiride decreased lever pressing, but produced only slight increases in chow intake at the highest dose. Pentobarbital reduced lever pressing and increased chow consumption at 10.0 mg/kg. The muscarinic agonist pilocarpine produced dose-related decreases in lever pressing, but failed to increase chow consumption. Amphetamine produced dose-related decreases in both lever pressing and chow consumption.(ABSTRACT TRUNCATED AT 250 WORDS)
