APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2022
·Vol. 88
·期 9
·
IF 5.005
Dong-Xu Jia,Fan Wang,Rui Zhao,Bo-Di Gu,Chen Peng,Li-Qun Jin,Zhi-Qiang Liu,Yu-Guo Zheng
d-Alanine belongs to nonessential amino acids that have diverse applications in the fields of food and health care. (R)-transaminase [(R)-TA]-catalyzed asymmetric amination of pyruvate is a feasible alternative for the synthesis of d-alanine, but low catalytic efficiency and thermostability limit enzymatic utilization. In this work, several potential (R)-TAs were discovered using NCBI database mining synchronously with enzymatic structure-function analysis, among which Capronia epimyces TA (CeTA) showed the highest activity for amination of pyruvate using (R)-α-methylbenzylamine as the donor. Furthermore, enzymatic residues surrounding a large catalysis pocket were subjected to saturation and combinatorial mutagenesis, and positive mutant F113T showed dramatic improvement in activity and thermostability. Molecular modeling indicated that the substitution of phenylalanine with threonine afforded alleviation of steric hindrance in the pocket and induced formation of additional hydrogen bonds with neighboring residues. Finally, using recombinant cells containing F113T as a biocatalyst, the conversion yield of amination of 100 mM pyruvate to d-alanine achieved up to 95.2%, which seemed to be the highest level in the literature regarding synthesis of d-alanine using TAs. The inherent characteristics rendered CeTA F113T a promising platform for efficient preparation of d-alanine operating with high productivity.IMPORTANCE d-Alanine is an important compound with many valuable applications. Its asymmetric synthesis employing (R)-ω-TA is considered an attractive choice. According to the stereoselectivity, ω-TAs have either (R)- or (S)-enantiopreference. There has been a variety of literature regarding screening, characterizing, and molecular modification of (S)-ω-TAs; in contrast, the research about (R)-ω-TA has lagged behind. In this work, we identify several (R)-ω-TAs and succeeded in creating mutant F113T, which showed not only better efficiency toward pyruvate but also higher thermostability compared with the original enzyme. The obtained original enzymes and positive mutants displayed important application value for pushing symmetric synthesis of d-alanine to a higher level.
研究领域:
生物技术
·
酶工程
·
化学生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
·
2024
·
IF 4.8
Rong Ma,Yuge Zhou,Weifan Huang,Xiaoni Kong
Ethnopharmacological relevance Epimedium Tourn. ex L. is a traditional Chinese medicine used for thousands of years in China to treat forgetfulness. Icariin is a principal component of the genus Epimedium . Aim of the study The metabolic mechanism of icariin treating forgetfulness is explored. Materials and methods A D-galactose-induced senescent mouse model was employed. The cognitive performance of mice was assessed in the fear conditioning test. Hippocampal pathology was assessed in the immunohistochemistry assay. Plasma metabolome was analyzed using GC-MS method, and the differential metabolites were further identified by UPLC-MS/MS or GC-MS method. The liver function, including ALT and AST, was assessed by enzyme reaction. Icariin was administered intraperitoneally at 50 and 100 mg/kg. Mice were administered five consecutive days per week for 8 weeks. Results Icariin treatment improved hippocampus-related fear memory but not amygdala-related memory, whereas Pexidartinib (PLX3397), a microglial scavenger, did not. Icariin treatment maintained the TMEM119-positive microglial population and decreased the accumulation of the senescent biomarker p16 in the dorsal hippocampus in senescent mouse brains, whereas PLX3397 did not. Notably, p16 in the CA2 subregion significantly decreased in icariin-treated mice than the other hippocampal subregions. The senescent mice exhibited the circulating metabolic characteristics of mild ketoacidosis, active tricarboxylic acid (TCA) cycle, lactic acidosis, hyperglycemia, active detoxification, active cis-oleic acid metabolism, and inhibitory GABA shut. R-3-hydroxybutyric acid primarily produced in the liver was selectively and robustly decreased by icariin treatment, which was not observed with PLX3397. The TCA cycle was rescued in senescent mice by icariin treatment. Icariin also protected liver function (plasma ALT) in D-gal-induced senescent mice. Conclusions Icariin may protect mouse hippocampal cognition from D-gal-induced senescence by protecting microglial homeostasis, and facilitating the utilization of R-3-hydroxybutyric acid is one of the underpins.
研究领域:
神经科学
·
药理学
·
代谢组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHIRALITY
·
2018
·Vol. 30
·期 6
·769-776
·
IF 1.833
Yilong Wang,Yongkai Xu,Yun Zhang,Aijun Sun,Yunfeng Hu
The two enantiomers of ethyl 3-hydroxybutyrate are important intermediates for the synthesis of a great variety of valuable chiral drugs. The preparation of chiral drug intermediates through kinetic resolution reactions catalyzed by esterases/lipases has been demonstrated to be an efficient and environmentally friendly method. We previously functionally characterized microbial esterase PHE21 and used PHE21 as a biocatalyst to generate optically pure ethyl ( S )-3-hydroxybutyrate. Herein, we also functionally characterized one novel salt-tolerant microbial esterase WDEst17 from the genome of Dactylosporangium aurantiacum subsp. Hamdenensis NRRL 18085. Esterase WDEst17 was further developed as an efficient biocatalyst to generate ( R )-3-hydroxybutyrate, an important chiral drug intermediate, with the enantiomeric excess being 99% and the conversion rate being 65.05%, respectively, after process optimization. Notably, the enantio-selectivity of esterase WDEst17 was opposite than that of esterase PHE21. The identification of esterases WDEst17 and PHE21 through genome mining of microorganisms provides useful biocatalysts for the preparation of valuable chiral drug intermediates.
研究领域:
生物化学
·
微生物学
·
药物合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2024
·
IF 3.4
Quan Luo,Guan Zhou,Zhongxia Li,Jiangpeng Dong,Hang Zhao,Huifang Xu,Xuefeng Lu
The chiral amine ( R )-2-(1-aminoethyl)-4-fluorophenol has attracted increasing attentions in recent years in the field of pharmaceuticals because of its important use as a building block in the synthesis of novel anti-tumor drugs targeting tropomyosin receptor kinases. In the present study, a ω-transaminase (ωTA) library consisting of 21 ( R )-enantioselective enzymes was constructed and screened for the asymmetric biosynthesis of ( R )-2-(1-aminoethyl)-4-fluorophenol from its prochiral ketone. Using ( R )-α-methylbenzylamine, D-alanine, or isopropylamine as amino donor, 18 ωTAs were identified with target activity and the enzyme AbTA, which was originally identified from Arthrobacter sp. KNK168, was found to be a potent candidate. The E. coli whole cells expressing AbTA could be used as catalysts. The optimal temperature and pH for the activity were 35–40 °C and pH8.0, respectively. Simple alcohols (such as ethanol, isopropanol, and methanol) and dimethyl sulfoxide were shown to be good cosolvents. High activities were detected when using ethanol and dimethyl sulfoxide at the concentrations of 5–20%. In the scaled-up reaction of 1-liter containing 13 mM ketone substrate, about 50% conversion was achieved in 24 h. 6.4 mM ( R )-2-(1-aminoethyl)-4-fluorophenol was generated. After a simple and efficient process of product isolation and purification (with 98.8% recovery), 0.986 g yellowish powder of the product ( R )-2-(1-aminoethyl)-4-fluorophenol with high ( R )-enantiopurity (up to 100% enantiomeric excess) was obtained. This study established an overall process for the biosynthesis of the high value pharmaceutical chiral amine ( R )-2-(1-aminoethyl)-4-fluorophenol by ωTA. Its applicable potential was exemplified by gram-scale production.
研究领域:
生物化学
·
制药工程
·
酶催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY
·
2016
·Vol. 34
·期 6
·1269-1277
·
IF 0.547
Liang Jiayuan,Sun Aijun,Zhang Yun,Deng Dun,Wang Yongfei,Ma Sanmei,Hu Yunfeng
Genomic mining has identified a novel microbial alkaline esterase from the Indian Ocean. This esterase was overexpressed in E. coli BL21 (DE3) and further functionally characterized. Under optimal conditions (10 mmol/L substrate, pH 6.0, 2 h at 40 °C), this esterase can hydrolyze racemic methyl mandelate to ( R )-methyl mandelate with very high optical purity ( e.e. >99%) and yield (nearly 90%). Interestingly, the stereoselectivity of this esterase is opposite to that of two previously reported lipases that can generate ( S )-methyl mandelate through the hydrolysis of racemic methyl mandelate. No organic solvents or other additives were required to optimize the optical purity and production of the final chiral product ( R )-methyl mandelate, which can potentially simplify the production procedure of ( R )-methyl mandelate catalyzed by esterase.
研究领域:
生物化学
·
海洋微生物学
·
酶工程
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Bairui Tao,Xiaoyan Feng,Fengjuan Miao
In order to solve the problem of glucose detection in medical development and meet the urgent demand for new energy storage devices, this paper proposes a new material suitable for glucose sensing and capacitive properties. The sensor was fabricated by depositing Co 3 O 4 nanoparticles onto nickel foam with integrated r-GO via the hydrothermal method, followed by the synthesis of CuO nanoparticles using electroplating. The detection range of the sensor is 0.3–11.3 mM. The sensor's sensitivity is 1000.3 μA mM −1 cm −2 , indicating its responsiveness to changes in analyte concentration. In electrochemical test systems, Signal-to-Noise Ratio (SNR) usually represents the relative intensity of the effective current signal and the background noise, reflecting the accuracy and reliability of the measurement. When the SNR is three, the minimum detection limit is 0.431 μM, highlighting its ability to reliably detect analytes at low concentrations amidst background noise. According to electrochemical workstation tests, the sensor demonstrates robust stability. Furthermore, the electrode material proves suitable for asymmetric supercapacitor devices, when the current density is 2 Ag −1 , the specific capacitance is 660.5 Fg −1 . At the same time, we also explore the cyclic stability of the device, which can retain 92.3 % of its initial specific capacitance after 5000 cycles, showing its remarkable long-term stability. In addition, the prepared nanocomposites can also light the red LED light. The results show that the synthesized CuO/Co 3 O 4 /r-GO/NF electrode can be used for electrochemical glucose sensing and supercapacitors, and plays an important role as a multi-functional material in the fields of medical, food, electronics, transportation and energy, providing key technical support for a variety of applications.
研究领域:
材料科学
·
医学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
LABORATORY INVESTIGATION
·
2022
·
IF 5.502
Ruo-Peng Liang,Xiao-Xue Zhang,Jie Zhao,Rong-Tao Zhu,Wei-Jie Wang,Qin-Wei Lu,Yu-Ling Sun
Ubiquitin-specific protease 3 (USP3), a kind of cysteine protease, is a crucial family member of deubiquitinating enzymes. USP3 is aberrantly expressed in several tumors, which may contribute to cancer progression. However, the role of USP3 in gallbladder cancer (GBC) is still unknown. In the current study, we detected the expression of USP3 in GBC tissues, measured its contribution to the cell proliferation in GBC progression, and further studied the underlying mechanism of USP3 in GBC through pyruvate kinase L/R (PKLR; a kind of glycolytic enzyme). We found that the expression of USP3 in GBC tissues were higher than that of adjacent tissues, and the protein levels of USP3 and PKLR were positively correlated. Additionally, overexpressed USP3 significantly promoted cell proliferation in vitro and tumor growth in vivo, while the silencing of USP3 inhibited proliferation and tumor growth. Glycolysis in GBC cells ws promoted by the USP3 overexpression and inhibited bye USP3 downregulation. Moreover, the loss of USP3 promoted the ubiquitination and weakened the stability of PKLR. Results of the rescue assay confirmed that PKLR knockdown suppressed USP3-induced oncogenic activity in USP3 overexpressed GBC cells. These findings imply that USP3 is an essential positive regulator in GBC progression, and USP3-PKLR plays a vital role in the progression and metabolism of GBC. Ubiquitin-specific protease 3 (USP3), a cysteine protease, is deubiquitinating enzyme. USP3 is aberrantly expressed in several types of tumors. The authors show that USP3 is an important positive regulator in gallbladder cancer progression, and that pyruvate kinase L/R plays a key role in the progression of GBC.
研究领域:
肿瘤学
·
分子生物学
·
癌症生物学
·
细胞生物学
✓ 已验证
DOI
PubMed
高影响因子
AMB Express
·
2021
·Vol. 11
·期 1
·1-13
·
IF 3.298
Zhuang Wenjin,Liu Hanyu,Zhang Ying,He Junyao,Wang Pu
( R )-1-[3-(Trifluoromethyl)phenyl]ethanol (( R )-MTF-PEL) is an important chiral building block for the synthesis of a neuroprotective compound, ( R )-3-(1-(3-(trifluoromethyl)phenyl)ethoxy)azetidine-1-carboxamide. In this work, an effective whole-cell-catalyzed biotransformation was developed to produce ( R )-MTF-PEL, and its productivity was increased by medium engineering strategy. The recombinant E. coli BL21(DE3)-pET28a(+) - LXCAR-S154Y variant affording carbonyl reductase was adopted for the reduction of 3'-(trifluoromethyl)acetophenone to ( R )-MTF-PEL with enantiomeric excess (ee) > 99.9%. The addition of 0.6% Tween-20 (w/v) boosted the bioreduction, because the substrate concentration was increased by 4.0-fold than that in the neat buffer solution. The biocatalytic efficiency was further enhanced by introducing choline chloride: lysine (ChCl:Lys, molar ratio of 1:1) in the reaction medium, because the product yield reached 91.5% under 200 mM substrate concentration in the established Tween-20/ChCl:Lys-containing system, which is the highest ever reported for ( R )-MTF-PEL production. The optimal reduction conditions were as follows: 4% (w/v) ChCl:Lys, 12.6 g (DCW)/L recombinant E. coli cells, pH 7.0, 30 ℃ and 200 rpm, reaction for 18 h. The combined strategy of surfactant and NADES has great potential in the biocatalytic process and the synthesis of chiral alcohols.
研究领域:
生物化学
·
合成生物学
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FISH & SHELLFISH IMMUNOLOGY
·
2023
·
IF 4.7
Lili Yun,Meiru Kang,Yihao Shen,Junchang Feng,Guokun Yang,Jianxin Zhang,Xiaolin Meng,Xulu Chang
This study aimed to evaluate the effects of dietary supplementation with Bacillus velezensis R-71003 combined with sodium gluconate on antioxidant capacity, immune response and resistance against Aeromonas hydrophila in common carp . In addition, the biocontrol potential of the secondary metabolites of B. velezensis R-71003 was also evaluated to analyze the possible mechanism of B. velezensis R-71003 against A. hydrophila . The results indicated that the antibacterial crude extract of B. velezensis R-71003 can destroy the cell wall of A. hydrophila . Moreover, the results showed that dietary B. velezensis R-71003 could promote antioxidant capacity, which significantly increased the activities of CAT and SOD and decreased the content of MDA. Additionally, B. velezensis R-71003 supplementation significantly enhanced the immunity of common carp, as measured by the mRNA expression levels of cytokine-related genes ( TNF-α , TGF-β , IL-1β and IL-10 ). In addition, dietary B. velezensis R-71003 exhibited an upregulation of IL-10 and a downregulation of IL-1β, coupled with higher survival rates when challenged with A. hydrophila compared to the positive group. Furthermore, compared to prechallenge, the mRNA expression levels of TLR-4 , MyD88 , IRAK1 , TRAF6 , TRIF and NF-κB in the head kidney of common carp were significantly increased after challenge. The fish fed the B. velezensis R-71003 diet showed lower expression of TLR-4 , MyD88 , IRAK1 , TRAF6 , TRIF and NF-κB after the challenge than those fed the control diet. Thus, this study revealed that B. velezensis R-71003 can improve the resistance of common carp to pathogenic bacteria by destroying bacterial cell walls and improving fish immunity by activating the TLR4 signaling pathway . Importantly, this study indicated that sodium gluconate has a positive effect on B. velezensis R-71003 in enhancing the anti-infection ability of common carp. The results of this study will lay the foundation for the application of B. velezensis R-71003 in combination with sodium gluconate as an alternative to antibiotics in aquaculture.
研究领域:
水产养殖学
·
微生物学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Zeyu Hu,Shouchun Xiao,Jianing Yao,Yue Cao,Bingying He,Jiaxing Yang,Fanrong Zhao,Li Zheng,Donghui Liu,Zhiqiang Zhou,Xueke Liu,Peng Wang
Famoxadone (FAM) is a widely used chiral fungicide that may contribute to metabolic dysfunction-associated fatty liver disease (MAFLD). However, the enantioselective toxicity and mechanism of action of famoxadone enantiomers remain unclear. The enantioselective bioaccumulation of famoxadone in mice was investigated, and the hepatotoxicity of famoxadone enantiomers, specifically in relation to MAFLD, was evaluated by a 12 week oral exposure to Rac-FAM, R-FAM, and S-FAM. R-FAM showed higher bioaccumulation than S-FAM, in which the concentrations of R-FAM were 3.52 and 242.69 times that of S-FAM in the liver at the no observed effect level (NOEL) and 1/10 NOEL, respectively. R-FAM was found to cause an increase in liver coefficients, a decrease in the AST/ALT ratio, enhanced expression of inflammation-related genes, and lipid droplet accumulation in the liver. In contrast, mice treated with S-FAM exhibited no significant changes in the quality of these indicators. These results suggest that R-famoxadone is more likely to be the dominant enantiomer affecting the liver. Furthermore, the important functional genes involved in glucose and lipid metabolism were detected. It was found that R-FAM significantly disrupted key lipid metabolic pathways in the liver, including glucose metabolism, fatty acid synthesis, triglyceride synthesis, and fatty acid β-oxidation. Additionally, R-FAM induced more severe disruptions in liver glucose and lipid metabolism compared to S-FAM. These research findings provide insights into the enantioselective toxicity of famoxadone enantiomers in terms of their role in promoting MAFLD development, contributing to the safe utilization of the chiral pesticide famoxadone.
研究领域:
毒理学
·
药理学
·
代谢生物学
✓ 已验证
DOI
PubMed
高影响因子
Pharmaceuticals
·
2025
·Vol. 18
·期 7
·1079
·
IF 4.8
Rui Wang,Yuqian Yang,Tong Zhou,Bingjie Zou,Li Ding
Objectives: (R)-ketamine hydrochloride injection is a novel, rapid-acting antidepressant for the treatment of treatment-resistant depression. The aim of this study was to assess the pharmacokinetics, safety, and tolerability of (R)-ketamine hydrochloride injection in healthy Chinese subjects following ascending single intravenous doses ranging from 10.0 mg to 180 mg.Methods: This randomized, double-blind, placebo-controlled study was conducted in 50 healthy male and female Chinese subjects after single ascending doses of (R)-ketamine hydrochloride injection (10.0, 30.0, 60.0, 120, and 180 mg). Ten subjects (including two subjects treated with a placebo) were included in each dose cohort. Pharmacokinetic characteristics, safety, and tolerability profiles of the study drug were evaluated.Results:After the intravenous doses administered from 10.0 mg to 180 mg of (R)-ketamine hydrochloride injection to the subjects, the Cmaxand AUC values for both (R)-ketamine and its metabolite (R)-norketamine in the subjects increased approximately proportionally to the doses. The average peak plasma concentration levels at the five dose cohorts ranged from 56.0 to 1424 ng/mL and 27.7 to 491 ng/mL for (R)-ketamine and (R)-norketamine, respectively. The adverse events of (R)-ketamine hydrochloride injection were temporary and recovered spontaneously without treatment.Conclusions: In summary, (R)-ketamine hydrochloride injection was safe and well tolerated in healthy Chinese subjects. The clinical study results laid a foundation for the further clinical studies of (R)-ketamine hydrochloride injection in patients.
研究领域:
药理学
·
临床医学
·
神经科学
·
精神病学
·
药物研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 13
·8079-8090
·
IF 4.22
Liu Jiali,Yang Qiang,Liu Jikai,Luo He’an
Tungsten trioxide (WO 3 ) has been conceived as a promising photoanode material for photoelectrochemical (PEC) water oxidation. Therefore, many efforts have been made to improve its PEC performances. Herein, a novel heterojunction is fabricated through combining rocksalt CoO (R-CoO) or blende CoO (B-CoO) nanosheets with WO 3 nanoplates using a spin-coating method. The typical type II heterojunctions, e.g., WO 3 /R-CoO and WO 3 /B-CoO, both have exhibited higher photocurrent densities than pristine WO 3 photoanode. The photocurrent densities of WO 3 /R-CoO, WO 3 /B-CoO and WO 3 are 0.53 mA cm −2 , 0.45 mA cm −2 and 0.31 mA cm −2 at 1.23 V vs. reversible hydrogen electrode, respectively. For the WO 3 /R-CoO photoanode, the surface charge separation efficiency is 50.95% and the photoconversion efficiency is 0.062%, which are both higher than the WO 3 and WO 3 /B-CoO photoanodes. The enhanced PEC performances are due to the type II heterojunction between WO 3 and R-CoO (or B-CoO), which facilitates the absorption of visible light and charge transport. The better performance of WO 3 /R-CoO than that of WO 3 /B-CoO may be due to the deeper valence band position of R-CoO. Our work demonstrates that R-CoO (or B-CoO) can couple with WO 3 to form a type II heterojunction to improve the PEC water oxidation performance.
研究领域:
材料科学
·
光电化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）