期刊文献+
共找到61,071篇文章
< 1 2 250 >
每页显示 20 50 100
Timosaponin AⅢ induces drug-metabolizing enzymes by activating constitutive androstane receptor (CAR) via dephosphorylation of the EGFR signaling pathway 被引量:1
1
作者 Muhammad Zubair Hafiz Jie Pan +4 位作者 Zhiwei Gao Ying Huo Haobin Wang Wei Liu Jian Yang 《Journal of Biomedical Research》 CAS CSCD 2024年第4期382-396,共15页
The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administratio... The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administration of T-AⅢ,the nude mice exhibited an induction of CYP2B10,MDR1,and CYP3A11 expression in the liver tissues.In the ICR mice,the expression levels of CYP2B10 and MDR1 increased after a three-day T-AⅢ administration.The in vitro assessments with HepG2 cells revealed that T-AⅢ induced the expression of CYP2B6,MDR1,and CYP3A4,along with constitutive androstane receptor(CAR)activation.Treatment with CAR siRNA reversed the T-AⅢ-induced increases in CYP2B6 and CYP3A4 expression.Furthermore,other CAR target genes also showed a significant increase in the expression.The up-regulation of murine CAR was observed in the liver tissues of both nude and ICR mice.Subsequent findings demonstrated that T-AⅢ activated CAR by inhibiting ERK1/2 phosphorylation,with this effect being partially reversed by the ERK activator t-BHQ.Inhibition of the ERK1/2 signaling pathway was also observed in vivo.Additionally,T-AⅢ inhibited the phosphorylation of EGFR at Tyr1173 and Tyr845,and suppressed EGF-induced phosphorylation of EGFR,ERK,and CAR.In the nude mice,T-AⅢ also inhibited EGFR phosphorylation.These results collectively indicate that T-AⅢ is a novel CAR activator through inhibition of the EGFR pathway. 展开更多
关键词 timosaponin AⅢ CAR metabolism enzyme ERK1/2 signaling pathway EGFR signaling pathway
下载PDF
Salvianolic acid B modulates the expression of drug-metabolizing enzymes in HepG2 cells 被引量:9
2
作者 Hani El-Nezami 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2011年第5期502-508,共7页
BACKGROUND: Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the... BACKGROUND: Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GSTs). Herbs that inhibit CYPs such as CYP3A4 or that induce GSTs may have the potential to protect against chemical carcinogenesis since the mutagenic effects of carcinogens are often mediated through an excess of CYP-generated reactive intermediates. This study was designed to investigate the effects of salvianolic acid B (Sal B), a pure compound extracted from Radix Salviae Miltiorrhizae, a Chinese herb, on cell proliferation and CYP1A2 and CYP3A4 mRNA expression in the presence or absence of rifampicin, a potent inducer of CYPs and GST protein expression in HepG2 cells. METHODS: HepG2 cells were incubated with different concentrations of Sal B. Cell proliferation was determined by SYTOX-Green nucleic acid staining. CYP3A4 and CYP1A2 mRNA expression was assayed by real-time PCR. GST protein expression was analyzed by Western blotting. RESULTS: Low concentrations of Sal B (0-20 μmol/L) had no significant effects on cell proliferation, while higher concentrations (100-250 μmol/L) significantly inhibited proliferation in a concentration-dependent manner. Ten μmol/L Sal B, but not 1 μmol/L, down-regulated CYP3A4 and CYP1A2 mRNA expression after 24 hours of incubation, whereas both 1 and 10 μmol/L Sal B down-regulated CYP3A4mRNA expression after 96 hours of incubation; moreover, 1 and 10 μmol/L Sal B inhibited CYP3A4 mRNA expression induced by rifampicin. Both 1 μmol/L and 10 μmol/L Sal B increased GST expression. CONCLUSION: Sal B inhibits CYP3A4 and CYP1A2 mRNA expression and induces GST expression in HepG2 cells. 展开更多
关键词 drug metabolizing enzymes CYP3A4 CYP1A2 glutathione S-transferases HepG2 cells Salvianolic acid B
下载PDF
Effects of Buyang Huanwu Decoction on antioxidant and drug-metabolizing enzymes in rat liver 被引量:3
3
作者 FAN Xing-Hua SHI Wei-Zhou +1 位作者 CHENG Yun-Xiang YANG Xiu-Fen 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2014年第6期449-454,共6页
AIM: To study the effect of Buyang Huanwu Decoction(BYHWD) on the antioxidant enzymes and drug-metabolizing enzymes in rat liver. METHOD: Following treatment of rats with BYHWD at 6.42, 12.83, or 25.66 g·kg–1 pe... AIM: To study the effect of Buyang Huanwu Decoction(BYHWD) on the antioxidant enzymes and drug-metabolizing enzymes in rat liver. METHOD: Following treatment of rats with BYHWD at 6.42, 12.83, or 25.66 g·kg–1 per day for 15 days, microsomes and cytosols isolated from the liver tissues were prepared by differential centrifugation according to standard procedures. The activities of the antioxidant enzymes and cytochrome b5, NADPH-cytochrome P450 reductase, CYP3 A, CYP2E1, UGT, and GST of the rat livers were determined by UV-Vis spectrophotometer. RESULTS: The activities of ALT, AST, antioxidant enzymes, and the Hepatosomatic Index in serum were not significantly affected. In cytosols, the activity of CAT was significantly increased at the dosage of 12.83 g·kg–1, and all the other antioxidant activities and MDA levels were not affected by this treatment. BYHWD had no effect on cytochrome b5, NADPH-cytochrome P450 reductase, CYP3 A, and UGT. At the highest dose(25.66 g·kg–1), the activity of CYP2E1 was significantly inhibited, and the activities of GST and the level of GSH were increased. CONCLUSION: BYHWD is safe for the liver, and has the functions of detoxification and antioxidant. Patients should be cautioned about the herb-drug interaction of BYHWD and CYP2E1 substrates. 展开更多
关键词 Buyang Huanwu Decoction ANTIOXIDANT drug-metabolizing enzymes
原文传递
Optical substrates for drug-metabolizing enzymes: Recent advances and future perspectives 被引量:2
4
作者 Qiang Jin Jing Jing Wu +4 位作者 Yue Wu Hongxin Li Moshe Finel Dandan Wang Guangbo Ge 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2022年第3期1068-1099,共32页
Drug-metabolizing enzymes(DMEs),a diverse group of enzymes responsible for the metabolic elimination of drugs and other xenobiotics,have been recognized as the critical determinants to drug safety and efficacy.Deciphe... Drug-metabolizing enzymes(DMEs),a diverse group of enzymes responsible for the metabolic elimination of drugs and other xenobiotics,have been recognized as the critical determinants to drug safety and efficacy.Deciphering and understanding the key roles of individual DMEs in drug metabolism and toxicity,as well as characterizing the interactions of central DMEs with xenobiotics require reliable,practical and highly specific tools for sensing the activities of these enzymes in biological systems.In the last few decades,the scientists have developed a variety of optical substrates for sensing human DMEs,parts of them have been successfully used for studying target enzyme(s)in tissue preparations and living systems.Herein,molecular design principals and recent advances in the development and applications of optical substrates for human DMEs have been reviewed systematically.Furthermore,the challenges and future perspectives in this field are also highlighted.The presented information offers a group of practical approaches and imaging tools for sensing DMEs activities in complex biological systems,which strongly facilitates high-throughput screening the modulators of target DMEs and studies on drug/herb-drug interactions,as well as promotes the fundamental researches for exploring the relevance of DMEs to human diseases and drug treatment outcomes. 展开更多
关键词 Optical substrates drug-metabolizing enzymes(DMEs) Fluorescence-based assay High-throughput screening
原文传递
Characterizing drug-metabolizing enzymes and transporters that are bona fide CAR-target genes in mouse intestine 被引量:1
5
作者 Shinhee Park Sunny Lihua Cheng Julia Yue Cui 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2016年第5期475-491,共17页
Intestine is responsible for the biotransformation of many orally-exposed chemicals.The constitutive androstane receptor(CAR/Nr1i3) is known to up-regulate many genes encoding drugmetabolizing enzymes and transporters... Intestine is responsible for the biotransformation of many orally-exposed chemicals.The constitutive androstane receptor(CAR/Nr1i3) is known to up-regulate many genes encoding drugmetabolizing enzymes and transporters(drug-processing genes/DPGs) in liver,but less is known regarding its effect in intestine.Sixty-day-old wild-type and Car / mice were administered the CARligand TCPOBOP or vehicle once daily for 4 days.In wild-type mice,Car m RNA was down-regulated by TCPOBOP in liver and duodenum.Car / mice had altered basal intestinal expression of many DPGs in a section-specific manner.Consistent with the liver data(Aleksunes and Klaassen,2012),TCPOBOP upregulated many DPGs(Cyp2b10,Cyp3a11,Aldh1a1,Aldh1a7,Gsta1,Gsta4,Gstm1-m4,Gstt1,Ugt1a1,Ugt2b34,Ugt2b36,and Mrp2–4) in specific sections of small intestine in a CAR-dependent manner.However,the m RNAs of Nqo1 and Papss2 were previously known to be up-regulated by TCPOBOP in liver but were not altered in intestine.Interestingly,many known CAR-target genes were highest expressed in colon where CAR is minimally expressed,suggesting that additional regulators are involved in regulating their expression.In conclusion,CAR regulates the basal expression of many DPGs in intestine,and although many hepatic CAR-targeted DPGs were bona fide CAR-targets in intestine,pharmacological activation of CAR in liver and intestine are not identical. 展开更多
关键词 Drug-processing genes INTESTINE Mice CAR drug-metabolizing enzymes Transporters
原文传递
Interactions of drug-metabolizing enzymes with the Chinese herb Psoraleae Fructus 被引量:11
6
作者 ZHOU Qi-Hang ZHU Ya-Di +5 位作者 ZHANG Feng SONG Yun-Qing JIA Shou-Ning ZHU Liang FANG Sheng-Quan GE Guang-Bo 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2019年第11期858-870,共13页
Psoraleae Fructus(the dried fruits of Psoralea corylifolia), one of the most frequently used Chinese herbs in Asian countries, has a variety of biological activities. In clinical settings, Psoraleae Fructus or Psorale... Psoraleae Fructus(the dried fruits of Psoralea corylifolia), one of the most frequently used Chinese herbs in Asian countries, has a variety of biological activities. In clinical settings, Psoraleae Fructus or Psoraleae Fructus-related herbal medicines frequently have been used in combination with a number of therapeutic drugs for the treatment of various human diseases, such as leukoderma, rheumatism and dysentery. The use of Psoraleae Fructus in combination with drugs has aroused concern of the potential risks of herb-drug interactions(HDI) or herb-endobiotic interactions(HEI). This article reviews the interactions between human drug-metabolizing enzymes and the constituents of Psoraleae Fructus;the major constituents in Psoraleae Fructus, along with their chemical structures and metabolic pathways are summarized, and the inhibitory and inductive effects of the constituents in Psoraleae Fructus on human drug-metabolizing enzymes(DMEs), including target enzyme(s), its modulatory potency, and mechanisms of action are presented. Collectively, this review summarizes current knowledge of the interactions between the Chinese herb Psoraleae Fructus and therapeutic drugs in an effort to facilitate its rational use in clinical settings, and especially to avoid the potential risks of HDI or HEI through human DMEs. 展开更多
关键词 Psoraleae Fructus Cytochrome P450 enzymes(CYPs) Uridine diphosphate-glucuronosyltransferases(UGTs) Herb-drug interactions(HDI) Herb-endobiotic interactions(HEI)
原文传递
Impact of obese levels on the hepatic expression of nuclear receptors and drug-metabolizing enzymes in adult and offspring mice
7
作者 Pei Wang Xueyan Shao +5 位作者 Yifan Bao Junjie Zhu Liming Chen Lirong Zhang Xiaochao Ma Xiao-bo Zhong 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2020年第1期171-185,共15页
The prevalence of obesity-associated conditions raises new challenges in clinical medication.Although altered expression of drug-metabolizing enzymes(DMEs)has been shown in obesity,the impacts of obese levels(overweig... The prevalence of obesity-associated conditions raises new challenges in clinical medication.Although altered expression of drug-metabolizing enzymes(DMEs)has been shown in obesity,the impacts of obese levels(overweight,obesity,and severe obesity)on the expression of DMEs have not been elucidated.Especially,limited information is available on whether parental obese levels affect ontogenic expression of DMEs in children.Here,a high-fat diet(HFD)and three feeding durations were used to mimic different obese levels in C57BL/6 mice.The hepatic expression of five nuclear receptors(NRs)and nine DMEs was examined.In general,a trend of induced expression of NRs and DMEs(except for Cyp2c29 and 3a11)was observed in HFD groups compared to low-fat diet(LFD)groups.Differentialeffects of HFD on the hepatic expression of DMEs were found in adult mice at different obese levels.Family-based dietary style of an HFD altered the ontogenic expression of DMEs in the offspring older than 15 days.Furthermore,obese levels of parental mice affected the hepatic expression of DMEs in offspring.Overall,the results indicate that obese levels affected expression of the DMEs in adult individuals and that of their children.Drug dosage might need to be optimized based on the obese levels. 展开更多
关键词 Diet-induced obesity OVERWEIGHT HIGH-FAT DIET drug-metabolizing enzymes Nuclear RECEPTORS Ontogenic EXPRESSION
原文传递
Engineering high amylose and resistant starch in maize by CRISPR/Cas9-mediated editing of starch branching enzymes
8
作者 Mingzheng Ma Shanqiu Sun +5 位作者 Jinjie Zhu Xiantao Qi Gaoke Li Jianguang Hu Chuanxiao Xie Changlin Liu 《The Crop Journal》 SCIE CSCD 2024年第4期1252-1258,共7页
To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).... To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).A frameshift mutation in SBEI(E1,a nucleotide insertion in exon 6)led to plants with higher RSC(1.07%),lower hundred-kernel weight(HKW,24.71±0.14 g),and lower plant height(PH,218.50±9.42 cm)compared to the wild type(WT).Like the WT,E1 kernel starch had irregular,polygonal shapes with sharp edges.A frameshift mutation in SBEIIb(E2,a four-nucleotide deletion in exon 8)led to higher AC(53.48%)and higher RSC(26.93%)than that for the WT.E2 kernel starch was significantly different from the WT regarding granule morphology,chain length distribution pattern,X-ray diffraction pattern,and thermal characteristics;the starch granules were more irregular in shape and comprised typical B-type crystals.Mutating SBEI and SBEIIb(E12)had a synergistic effect on RSC,HKW,PH,starch properties,and starch biosynthesis-associated gene expression.SBEIIa,SS1,SSIIa,SSIIIa,and SSIIIb were upregulated in E12 endosperm compared to WT endosperm.This study lays the foundation for rapidly improving the starch properties of elite maize lines. 展开更多
关键词 MAIZE Gene editing Starch branching enzyme I Starch branching enzyme IIb
下载PDF
Mutagenicity and Induction of Drug-metabolizing Enzyme Activity by LPG Combustion Particulates in Rats
9
作者 YIN XUE-JUN LIU JUN-ZHUO +3 位作者 LI YONG-SHUN KONG XIANG-HUAN AND LIU HONG(Department of Environmental Health, Capital University of Medical Sciences, Beijing 100054, China Department of Environmental Health, Beijing Medical University, Beijing, China) 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1994年第4期346-356,共11页
Methylene chloride extracts of particulates from liquefied petroleum gas (LPG) combustion appliance were studied by using Ames test, micronucleus test and inducibility of pulmonary and hepatic aryl hydrocarbon hydroxy... Methylene chloride extracts of particulates from liquefied petroleum gas (LPG) combustion appliance were studied by using Ames test, micronucleus test and inducibility of pulmonary and hepatic aryl hydrocarbon hydroxylase (AHH) and glutathione S-transferase (GST) in rats. The extracts showed mutagenicity for Salmonella typhimurium strain TA98 and its derivatives TA98NR and TA98/1,8-DNP6 with or without S9 mix. The revertants in strains TA98NR and TA98/1,8-DNP6 were less than 40% and 50% of that in strain TA98 without S9 mix, respectively. Positive results were obtained in mouse bone marrow micronucleus assay. Intratracheal instillation of the extracts led to increase in pulmonary (but not hepatic) AHH and GST activities in rats. It was seen that AHH was more sensitive than GST to induction by the extracts 展开更多
关键词 ACTIVITY Mutagenicity and Induction of drug-metabolizing enzyme Activity by LPG Combustion Particulates in Rats DNP LPG
下载PDF
The Effect of Soil Enzymes and Polysaccharides Secreted by the Roots of Salvia miltiorrhiza Bunge under Drought,High Temperature,and Nitrogen and Phosphorus Deficits
10
作者 Yong Qin Xiaoyu Li +3 位作者 Yanhong Wu Hai Wang Guiqi Han Zhuyun Yan 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第1期119-135,共17页
Root exudates serve as crucial mediators for information exchange between plants and soil,and are an important evolutionary mechanism for plants’adaptation to environmental changes.In this study,15 different abiotic ... Root exudates serve as crucial mediators for information exchange between plants and soil,and are an important evolutionary mechanism for plants’adaptation to environmental changes.In this study,15 different abiotic stress models were established using various stress factors,including drought(D),high temperature(T),nitrogen deficiency(N),phosphorus deficiency(P),and their combinations.We investigated their effects on the seedling growth of Salvia miltiorrhiza Bunge and the activities of Solid-Urease(S-UE),Solid-Nitrite Reductase(S-NiR),Solid-Nitrate Reductase(S-NR),Solid-Phosphotransferase(S-PT),and Solid-Catalase(S-CAT),as well as the contents of polysaccharides in the culture medium.The results showed that the growth of S.miltiorrhiza was inhibited under 15 stress conditions.Among them,13 stress conditions increased the root-shoot ratio.These 15 stress conditions significantly reduced the activity of S-NR,two combinations significantly improved the activity of S-NIR,they were synergistic stresses of high temperature and nitrogen deficiency(TN),and synergistic stresses of drought and nitrogen deficiency(DN)(p<0.05).The activity of S-UE was significantly improved under N,D,T,synergistic stresses of drought and high temperature(DT),DN,synergistic stresses of drought and phosphorus deficiency(DP),and synergistic stresses of high temperature,nitrogen,and phosphorus deficiency(TNP)stress conditions(p<0.05).Most stress combinations reduced the activity of S-PT,but D and T significantly improved it.(p<0.05).The N,DN,and TN stress conditions significantly reduced S-CAT activity.The P,DT,and synergistic stresses of drought,high temperature,and phosphorus deficiency(DTP)significantly decreased the total polysaccharide content of the soil(p<0.05).The research suggested that abiotic stress hindered the growth of S.miltiorrhiza and altered the behavior of root secretion.Roots regulated the secretion of several substances in response to various abiotic stresses,including soil nitrogen cycle enzymes,phosphorus transport-related enzymes,and antioxidant enzymes.In conclusion,plants regulate the utilization of rhizosphere substances in response to abiotic stresses by modulating the exudation of soil enzymes and polysaccharides by the root system.At the same time,soil carbon sequestration was affected by the adverse environment,which restricted the input of organic matter into the soil. 展开更多
关键词 Abiotic stress Salvia miltiorrhiza soil enzymes total polysaccharides soil carbon sequestration
下载PDF
Screening for metabolic dysfunction-associated fatty liver disease:Time to discard the emperor’s clothes of normal liver enzymes?
11
作者 Chen-Xiao Huang Xiao-Dong Zhou +1 位作者 Calvin Q Pan Ming-Hua Zheng 《World Journal of Gastroenterology》 SCIE CAS 2024年第22期2839-2842,共4页
Metabolic dysfunction-associated fatty liver disease(MAFLD)is the most prevalent chronic liver condition worldwide.Current liver enzyme-based screening methods have limitations that may missed diagnoses and treatment ... Metabolic dysfunction-associated fatty liver disease(MAFLD)is the most prevalent chronic liver condition worldwide.Current liver enzyme-based screening methods have limitations that may missed diagnoses and treatment delays.Regarding Chen et al,the risk of developing MAFLD remains elevated even when alanine aminotransferase levels fall within the normal range.Therefore,there is an urgent need for advanced diagnostic techniques and updated algorithms to enhance the accuracy of MAFLD diagnosis and enable early intervention.This paper proposes two potential screening methods for identifying individuals who may be at risk of developing MAFLD:Lowering these thresholds and promoting the use of noninvasive liver fibrosis scores. 展开更多
关键词 Metabolic dysfunction-associated fatty liver disease Non-alcoholic fatty liver disease Alanine aminotransferase Liver enzymes SCREENING Noninvasive liver fibrosis scores
下载PDF
Expression level of myocardial enzymes in patients with schizophrenia: Predictive value in the occurrence of violence
12
作者 Wei-Min He Xin-Yuan Zhang +2 位作者 Wei-Gen Xie Dan-Ping Lv Qun-Di Shen 《World Journal of Psychiatry》 SCIE 2024年第9期1346-1353,共8页
BACKGROUND Schizophrenic patients are prone to violence,frequent recurrence,and difficult to predict.Emotional and behavioral abnormalities during the onset of the disease,resulting in active myocardial enzyme spectru... BACKGROUND Schizophrenic patients are prone to violence,frequent recurrence,and difficult to predict.Emotional and behavioral abnormalities during the onset of the disease,resulting in active myocardial enzyme spectrum.AIM To explored the expression level of myocardial enzymes in patients with schizo-phrenia and its predictive value in the occurrence of violence.METHODS A total of 288 patients with schizophrenia in our hospital from February 2023 to January 2024 were selected as the research object,and 100 healthy people were selected as the control group.Participants’information,clinical data,and labo-ratory examination data were collected.According to Modified Overt Aggression Scale score,patients were further divided into the violent(123 cases)and non-violent group(165 cases).RESULTS The comparative analysis revealed significant differences in serum myocardial enzyme levels between patients with schizophrenia and healthy individuals.In the schizophrenia group,the violent and non-violent groups also exhibited different levels of serum myocardial enzymes.The levels of myocardial enzymes in the non-violent group were lower than those in the violent group,and the patients in the latter also displayed aggressive behavior in the past.CONCLUSION Previous aggressive behavior and the level of myocardial enzymes are of great significance for the diagnosis and prognosis analysis of violent behavior in patients with schizophrenia.By detecting changes in these indicators,we can gain a more comprehensive understanding of a patient’s condition and treatment. 展开更多
关键词 SCHIZOPHRENIA Myocardial enzyme index Act of violence PREDICT Violence prediction Aggressive behavior Clinical data analysis Biochemical markers
下载PDF
Recent advances in immobilized enzymes on nanocarriers 被引量:12
13
作者 曹诗林 徐培 +5 位作者 马永正 姚潇晓 姚远 宗敏华 李雪辉 娄文勇 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第11期1814-1823,共10页
Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high cataly... Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance,enhanced stabilities,improved enzyme-substrate affinities,and reusabilities.Many studies have been performed to investigate the efficient use of cellulose nanocrystals,polydopamine-based nanomaterials,and synthetic polymer nanogels for enzyme immobilization.Various nanobiocatalysts are highlighted in this review,with the emphasis on the design,preparation,properties,and potential applications of nanoscale enzyme carriers and nanobiocatalysts. 展开更多
关键词 enzyme immobilization Cellulose nanocrystal POLYDOPAMINE Biodegradable material
下载PDF
Effect of ^(12)C^(6+) Ions Beam Irradiation on Seed Germination and Enzymes Activity in Seedlings of Sweet Sorghum 被引量:10
14
作者 冯亮英 董喜存 +7 位作者 李文建 马晓琪 马爽 余丽霞 李岩 刘清芳 何金玉 曲颖 《Agricultural Science & Technology》 CAS 2009年第5期22-25,共4页
[ Objective] The aim was to study the effect of 12C6 + ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretic... [ Objective] The aim was to study the effect of 12C6 + ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretical foundation for sweet sorghum breeding. [ Method] After germination, the germination potential, germination fraction and enzyme activity were detected, respectively. [ Result] The results showed that with the dose increased, the germination potential of sweet sorghum increased first and then decreased, while their germination fraction presented "shoulder like shape" ; the activity of LDH, SOD, CAT and GSH-Px increased first and then decreased with doses, they presented slight differences among different enzymes. [ Conclusion] Low dose radiation could accelerate germination of sweet sorghum seeds and enzyme activity could remain at a relatively high level. Enzyme activity decreased with high doses and the growth of sweet sorghum was inhibited. 展开更多
关键词 Heavy ions Sweet sorghum Germination potential Seedling rate enzyme activity
下载PDF
Effect of Different Arbuscular Mycorrhizal Fungi Strains on Mineral Nutrition and Antioxidant Enzymes of Chrysanthemum morifolium 被引量:12
15
作者 孔佩佩 杨树华 +1 位作者 贾瑞冬 葛红 《Agricultural Science & Technology》 CAS 2011年第10期1477-1480,共4页
[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains(AMF)on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was con... [Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains(AMF)on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium 'Jinba' was inoculated with five kinds of AMF,N,P,K,malondial dehyde(MDA)content,as well as the superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium. 展开更多
关键词 Chrysanthemum morifolium Arbuscular mycorrhizal fungi Mineral nutrition Antioxidant enzymes
下载PDF
Effects of two kinds of transgenic poplar on protective enzymes system in the midgut of larvae of American white moth 被引量:10
16
作者 丁双阳 孟秀芹 李学锋 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第2期119-122,147,共4页
The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-i... The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar. 展开更多
关键词 Transgenic poplar American white moth Protective enzyme system
下载PDF
Effects of Adaptation to Elevated Salinity on Some Enzymes' Salt_tolerance in Vitro and Physiological Changes of Eelgrass 被引量:20
17
作者 叶春江 赵可夫 《Acta Botanica Sinica》 CSCD 2002年第7期788-794,共7页
The eelgrass ( Zostera marina L.) was treated with artificial seawater (ASW) of different salinities ( 100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determin... The eelgrass ( Zostera marina L.) was treated with artificial seawater (ASW) of different salinities ( 100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determined under a salinity grade in vitro So were the photosynthesis rates of the plants from the three treatments in the media with different salinities 100%, 150%, 200%, 300% ASW) and Some physiological data. The data showed that under increased salinities (concentrated seawater), Na+, Cl-, MDA (malon dialdehyde) and glucose contents and the osmotic potentials ( absolute value) in the leaves increased with the salinity elevation in the medium (ASW), but both K+ and free amino acid (mainly proline) contents decreased. Malate dehydrogenase (MDH) from the plant leaves under a salinity grade showed its activities (A) as follows: A(100%) (ASW) > A(150%) (ASW) > A(200%) (ASW). Phosphoenolpyruvate carboxylase (PEPC) extracted from the 100% ASW- and 200% ASW-treated plants showed similar activities (both insensitive to salinities) under the salinity grade in vitro, but the activities of PEPC from plants treated with 150% ASW were dependent oil salinity. Whether the plant is stressed at 150% ASW and can stand higher salinity than seawater needs to be studied further. Meantime, die data do not agree with the opinion that the adaptation of the eelgrass to seawater salinity is partly fulfilled by its insensitiveness to salinities in Some metabolic enzymes. It can be inferred that the lack of transpiration may be an important aspect of tire plant's tolerance to seawater salinity. 展开更多
关键词 EELGRASS salinity adaptation enzyme salt tolerance PEPC MDHI MDA
下载PDF
Research on Activities of Antioxidant Enzymes during Pigment Gland Morphogenesis in Cotton 被引量:1
18
作者 谢永芳 梁亦龙 +2 位作者 米瑶 刘潇淇 蔡应繁 《Agricultural Science & Technology》 CAS 2012年第1期44-48,共5页
[Objective] This study aimed to determine activities of antioxidant enzymes during gland morphogenesis in cotton, thoroughly explore physiological changes of cotton and provide a scientific basis for the cultivation o... [Objective] This study aimed to determine activities of antioxidant enzymes during gland morphogenesis in cotton, thoroughly explore physiological changes of cotton and provide a scientific basis for the cultivation of excellent cotton varieties. [Method] Based on determination of gossypol contents and antioxidant enzymes ac- tivities during gland morphogenesis in three cotton varieties (Chuanmian2802, Xiang- mian18 and XianwuN5), metabolism of gossypol and morphogenesis of gland in cot- ton were explored. [Result] After gland morphogenesis, the content of gossypol in Chuanmian2802 was gradually reduced in the early period of seed germination, which slowly increased since the 5th d after germination; however, during the seed germination period, the content of gossypol in Xiangmian18 had a slowly increasing trend and was gradually close to the content of gossypol in Chuanmian2802. The results showed that activities of SOD, POD and CAT increased in seed germination, which was contributive to remove the superoxide radicals, decrease the peroxide lev- el, reduce damages to the membrane, enhance the body's resistance to lipid oxida- tion and increase resistance ability to stress. [Conclusion] This study laid the scientif- ic foundation for understanding the characteristics of gland morphogenesis in cotton and cotton cultivation by using gland traits. 展开更多
关键词 GLAND GOSSYPOL -A-ntioxidant enzymes
下载PDF
Advances in Activity of Related Enzymes during Graft Healing Process of Citrus Paradisi Macf 被引量:1
19
作者 严毅 高柱 +1 位作者 何承忠 李贤忠 《Agricultural Science & Technology》 CAS 2011年第10期1472-1476,共5页
The distribution and ecological characters of grapefruit were analyzed mainly,and the research trends of stock and scion selection for grafting,the healing-anatomy process and enzymology were summarized systematically... The distribution and ecological characters of grapefruit were analyzed mainly,and the research trends of stock and scion selection for grafting,the healing-anatomy process and enzymology were summarized systematically.The results indicated that the range of stock and scion apolegamy decreased through the application of molecular technique.But the study on stock variety and scion selection was still in need of expanding and the key enzyme played a vital role in the healing of the stock and scion,which provided a chance for the regulation and control of healing force by hormones and also provided a theoretical basis for the regulation of gene. 展开更多
关键词 GRAPEFRUIT Graft healing enzyme activity
下载PDF
Synthesis of kanamycin A derivatives by regioselective masking drug resistant enzymes targeting hydroxyl groups
20
作者 陈颖 孟祥豹 +2 位作者 陈桂辉 潘攀 李中军 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第2期138-143,共6页
The 3'-OH, 4'-OH and 2"-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. T... The 3'-OH, 4'-OH and 2"-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A. 展开更多
关键词 Aminoglycoisdes Kanamycin A derivatives Resistant enzyme Regioselectivity
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部