Enzyme Research最新文献_第9页

Cloning, Expression, and Purification of Nucleoside Diphosphate Kinase from Acinetobacter baumannii. 鲍曼不动杆菌核苷二磷酸激酶的克隆、表达和纯化。

Enzyme Research Pub Date : 2013-01-01 Epub Date: 2013-04-11 DOI: 10.1155/2013/597028

Juhi Sikarwar, Sanket Kaushik, Mau Sinha, Punit Kaur, Sujata Sharma, Tej P Singh

引用次数: 0

In silico characterization of histidine Acid phytase sequences. 组氨酸植酸酶序列的硅学特征。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-12-05 DOI: 10.1155/2012/845465

Vinod Kumar, Gopal Singh, A K Verma, Sanjeev Agrawal

{"title":"In silico characterization of histidine Acid phytase sequences.","authors":"Vinod Kumar, Gopal Singh, A K Verma, Sanjeev Agrawal","doi":"10.1155/2012/845465","DOIUrl":"10.1155/2012/845465","url":null,"abstract":"Histidine acid phytases (HAPhy) are widely distributed enzymes among bacteria, fungi, plants, and some animal tissues. They have a significant role as an animal feed enzyme and in the solubilization of insoluble phosphates and minerals present in the form of phytic acid complex. A set of 50 reference protein sequences representing HAPhy were retrieved from NCBI protein database and characterized for various biochemical properties, multiple sequence alignment (MSA), homology search, phylogenetic analysis, motifs, and superfamily search. MSA using MEGA5 revealed the presence of conserved sequences at N-terminal \"RHGXRXP\" and C-terminal \"HD.\" Phylogenetic tree analysis indicates the presence of three clusters representing different HAPhy, that is, PhyA, PhyB, and AppA. Analysis of 10 commonly distributed motifs in the sequences indicates the presence of signature sequence for each class. Motif 1 \"SPFCDLFTHEEWIQYDYLQSLGKYYGYGAGNPLGPAQGIGF\" was present in 38 protein sequences representing clusters 1 (PhyA) and 2 (PhyB). Cluster 3 (AppA) contains motif 9 \"KKGCPQSGQVAIIADVDERTRKTGEAFAAGLAPDCAITVHTQADTSSPDP\" as a signature sequence. All sequences belong to histidine acid phosphatase family as resulted from superfamily search. No conserved sequence representing 3- or 6-phytase could be identified using multiple sequence alignment. This in silico analysis might contribute in the classification and future genetic engineering of this most diverse class of phytase.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"845465"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3523131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31147492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of enzyme catalysis in calcium alginate beads. 海藻酸钙微球酶催化的模拟。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-10-31 DOI: 10.1155/2012/459190

Ameel M R Al-Mayah

{"title":"Simulation of enzyme catalysis in calcium alginate beads.","authors":"Ameel M R Al-Mayah","doi":"10.1155/2012/459190","DOIUrl":"https://doi.org/10.1155/2012/459190","url":null,"abstract":"A general mathematical model for a fixed bed immobilized enzyme reactor was developed to simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α-amylase were used as a model for this study. Corn starch hydrolysis was carried out at a constant pH of 5.5 and temperature of 50°C. The substrate flow rate was ranging from 0.2 to 5.0 mL/min, substrate initial concentrations 1 to 100 g/L. α-amylase was immobilized on to calcium alginate hydrogel beads of 2 mm average diameter. In this work Michaelis-Menten kinetics have been considered. The effect of substrate flow rate (i.e., residence time) and initial concentration on intraparticle diffusion have been taken into consideration. The performance of the system is found to be affected by the substrate flow rate and initial concentrations. The reaction is controlled by the reaction rate. The model equation was a nonlinear second order differential equation simulated based on the experimental data for steady state condition. The simulation was achieved numerically using FINITE ELEMENTS in MATLAB software package. The simulated results give satisfactory results for substrate and product concentration profiles within the biocatalyst bead.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"459190"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/459190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31084275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Isolation and characterization of chitosan-producing bacteria from beaches of chennai, India. 印度金奈海滩产壳聚糖细菌的分离与鉴定。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-08-05 DOI: 10.1155/2012/421683

Kuldeep Kaur, Vikrant Dattajirao, Vikas Shrivastava, Uma Bhardwaj

引用次数: 46

Use of fluorochrome-labeled inhibitors of caspases to detect neuronal apoptosis in the whole-mounted lamprey brain after spinal cord injury. 用荧光标记的半胱氨酸酶抑制剂检测脊髓损伤后全载七鳃鳗脑内神经元凋亡。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-07-08 DOI: 10.1155/2012/835731

Antón Barreiro-Iglesias, Michael I Shifman

{"title":"Use of fluorochrome-labeled inhibitors of caspases to detect neuronal apoptosis in the whole-mounted lamprey brain after spinal cord injury.","authors":"Antón Barreiro-Iglesias, Michael I Shifman","doi":"10.1155/2012/835731","DOIUrl":"https://doi.org/10.1155/2012/835731","url":null,"abstract":"Apoptosis is a major feature in neural development and important in traumatic diseases. The presence of active caspases is a widely accepted marker of apoptosis. We report here the development of a method to study neuronal apoptotic death in whole-mounted brain preparations using fluorochrome-labeled inhibitors of caspases (FLICA). As a model we used axotomy-induced retrograde neuronal death in the CNS of larval sea lampreys. Once inside the cell, the FLICA reagents bind covalently to active caspases causing apoptotic cells to fluoresce, whereas nonapoptotic cells remain unstained. The fluorescent probe, the poly caspase inhibitor FAM-VAD-FMK, was applied to whole-mounted brain preparations of larval sea lampreys 2 weeks after a complete spinal cord (SC) transection. Specific labeling occurred only in identifiable spinal-projecting neurons of the brainstem previously shown to undergo apoptotic neuronal death at later times after SC transection. These neurons also exhibited intense labeling 2 weeks after a complete SC transection when a specific caspase-8 inhibitor (FAM-LETD-FMK) served as the probe. In this study we show that FLICA reagents can be used to detect specific activated caspases in identified neurons of the whole-mounted lamprey brain. Our results suggest that axotomy may cause neuronal apoptosis by activation of the extrinsic apoptotic pathway.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"835731"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/835731","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30788305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 33

Production of Biomass-Degrading Multienzyme Complexes under Solid-State Fermentation of Soybean Meal Using a Bioreactor. 生物反应器固态发酵豆粕生产生物质降解复合酶的研究。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-12-29 DOI: 10.1155/2012/248983

Gabriela L Vitcosque, Rafael F Fonseca, Ursula Fabiola Rodríguez-Zúñiga, Victor Bertucci Neto, Sonia Couri, Cristiane S Farinas

{"title":"Production of Biomass-Degrading Multienzyme Complexes under Solid-State Fermentation of Soybean Meal Using a Bioreactor.","authors":"Gabriela L Vitcosque, Rafael F Fonseca, Ursula Fabiola Rodríguez-Zúñiga, Victor Bertucci Neto, Sonia Couri, Cristiane S Farinas","doi":"10.1155/2012/248983","DOIUrl":"https://doi.org/10.1155/2012/248983","url":null,"abstract":"Biomass-degrading enzymes are one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels. This work evaluates the effects of operational conditions on biomass-degrading multienzyme production by a selected strain of Aspergillus niger. The fungus was cultivated under solid-state fermentation (SSF) of soybean meal, using an instrumented lab-scale bioreactor equipped with an on-line automated monitoring and control system. The effects of air flow rate, inlet air relative humidity, and initial substrate moisture content on multienzyme (FPase, endoglucanase, and xylanase) production were evaluated using a statistical design methodology. Highest production of FPase (0.55 IU/g), endoglucanase (35.1 IU/g), and xylanase (47.7 IU/g) was achieved using an initial substrate moisture content of 84%, an inlet air humidity of 70%, and a flow rate of 24 mL/min. The enzymatic complex was then used to hydrolyze a lignocellulosic biomass, releasing 4.4 g/L of glucose after 36 hours of saccharification of 50 g/L pretreated sugar cane bagasse. These results demonstrate the potential application of enzymes produced under SSF, thus contributing to generate the necessary technological advances to increase the efficiency of the use of biomass as a renewable energy source.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"248983"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/248983","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31200309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 42

Statistical Approach for Optimization of Physiochemical Requirements on Alkaline Protease Production from Bacillus licheniformis NCIM 2042. 地衣芽孢杆菌NCIM 2042产碱性蛋白酶理化条件优化的统计方法

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-01-05 DOI: 10.1155/2012/905804

Biswanath Bhunia, Apurba Dey

{"title":"Statistical Approach for Optimization of Physiochemical Requirements on Alkaline Protease Production from Bacillus licheniformis NCIM 2042.","authors":"Biswanath Bhunia, Apurba Dey","doi":"10.1155/2012/905804","DOIUrl":"https://doi.org/10.1155/2012/905804","url":null,"abstract":"The optimization of physiochemical parameters for alkaline protease production using Bacillus licheniformis NCIM 2042 were carried out by Plackett-Burman design and response surface methodology (RSM). The model was validated experimentally and the maximum protease production was found 315.28 U using optimum culture conditions. The protease was purified using ammonium sulphate (60%) precipitation technique. The HPLC analysis of dialyzed sample showed that the retention time is 1.84 min with 73.5% purity. This enzyme retained more than 92% of its initial activity after preincubation for 30 min at 37°C in the presence of 25% v/v DMSO, methanol, ethanol, ACN, 2-propanol, benzene, toluene, and hexane. In addition, partially purified enzyme showed remarkable stability for 60 min at room temperature, in the presence of anionic detergent (Tween-80 and Triton X-100), surfactant (SDS), bleaching agent (sodium perborate and hydrogen peroxide), and anti-redeposition agents (Na(2)CMC, Na(2)CO(3)). Purified enzyme containing 10% w/v PEG 4000 showed better thermal, surfactant, and local detergent stability.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"905804"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/905804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30471045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 46

The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus. Arg13在长聚热球菌蛋白磷酸酶M tPphA中的作用。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-06-06 DOI: 10.1155/2012/272706

Jiyong Su, Karl Forchhammer

{"title":"The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus.","authors":"Jiyong Su, Karl Forchhammer","doi":"10.1155/2012/272706","DOIUrl":"https://doi.org/10.1155/2012/272706","url":null,"abstract":"A highly conserved arginine residue is close to the catalytic center of PPM/PP2C-type protein phosphatases. Different crystal structures of PPM/PP2C homologues revealed that the guanidinium side chain of this arginine residue can adopt variable conformations and may bind ligands, suggesting an important role of this residue during catalysis. In this paper, we randomly mutated Arginine 13 of tPphA, a PPM/PP2C-type phosphatase from Thermosynechococcus elongatus, and obtained 18 different amino acid variants. The generated variants were tested towards p-nitrophenyl phosphate and various phosphopeptides. Towards p-nitrophenyl phosphate as substrate, twelve variants showed 3-7 times higher K(m) values than wild-type tPphA and four variants (R13D, R13F, R13L, and R13W) completely lost activity. Strikingly, these variants were still able to dephosphorylate phosphopeptides, although with strongly reduced activity. The specific inability of some Arg-13 variants to hydrolyze p-nitrophenyl phosphate highlights the importance of additional substrate interactions apart from the substrate phosphate for catalysis. The properties of the R13 variants indicate that this residue assists in substrate binding.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"272706"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/272706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30707873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Correlation between Agar Plate Screening and Solid-State Fermentation for the Prediction of Cellulase Production by Trichoderma Strains. 预测毛霉菌株纤维素酶产量的琼脂平板筛选与固态发酵之间的相关性

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-11-28 DOI: 10.1155/2012/793708

Camila Florencio, Sonia Couri, Cristiane Sanchez Farinas

{"title":"Correlation between Agar Plate Screening and Solid-State Fermentation for the Prediction of Cellulase Production by Trichoderma Strains.","authors":"Camila Florencio, Sonia Couri, Cristiane Sanchez Farinas","doi":"10.1155/2012/793708","DOIUrl":"10.1155/2012/793708","url":null,"abstract":"The viability of converting biomass into biofuels and chemicals still requires further development towards the reduction of the enzyme production costs. Thus, there is a growing demand for the development of efficient procedures for selection of cellulase-producing microorganisms. This work correlates qualitative screening using agar plate assays with quantitative measurements of cellulase production during cultivation under solid-state fermentation (SSF). The initial screening step consisted of observation of the growth of 78 preselected strains of the genus Trichoderma on plates, using microcrystalline cellulose as carbon source. The 49 strains that were able to grow on this substrate were then subjected to a second screening step using the Congo red test. From this test it was possible to select 10 strains that presented the highest enzymatic indices (EI), with values ranging from 1.51 to 1.90. SSF cultivations using sugarcane bagasse and wheat bran as substrates were performed using selected strains. The CG 104NH strain presented the highest EGase activity (25.93 UI·g(-1)). The EI results obtained in the screening procedure using plates were compared with cellulase production under SSF. A correlation coefficient (R(2)) of 0.977 was obtained between the Congo red test and SSF, demonstrating that the two methodologies were in good agreement.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2012 ","pages":"793708"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3514834/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31111748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Insights into the in vivo regulation of glutamate dehydrogenase from the foot muscle of an estivating land snail. 谷氨酸脱氢酶在体内调节的见解从一个正在生长的蜗牛足部肌肉。

Enzyme Research Pub Date : 2012-01-01 Epub Date: 2012-03-26 DOI: 10.1155/2012/317314

Ryan A V Bell, Neal J Dawson, Kenneth B Storey

{"title":"Insights into the in vivo regulation of glutamate dehydrogenase from the foot muscle of an estivating land snail.","authors":"Ryan A V Bell, Neal J Dawson, Kenneth B Storey","doi":"10.1155/2012/317314","DOIUrl":"https://doi.org/10.1155/2012/317314","url":null,"abstract":"Land snails, Otala lactea, survive in seasonally hot and dry environments by entering a state of aerobic torpor called estivation. During estivation, snails must prevent excessive dehydration and reorganize metabolic fuel use so as to endure prolonged periods without food. Glutamate dehydrogenase (GDH) was hypothesized to play a key role during estivation as it shuttles amino acid carbon skeletons into the Krebs cycle for energy production and is very important to urea biosynthesis (a key molecule used for water retention). Analysis of purified foot muscle GDH from control and estivating conditions revealed that estivated GDH was approximately 3-fold more active in catalyzing glutamate deamination as compared to control. This kinetic difference appears to be regulated by reversible protein phosphorylation, as indicated by ProQ Diamond phosphoprotein staining and incubations that stimulate endogenous protein kinases and phosphatases. The increased activity of the high-phosphate form of GDH seen in the estivating land snail foot muscle correlates well with the increased use of amino acids for energy and increased synthesis of urea for water retention during prolonged estivation.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":" ","pages":"317314"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/317314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40184605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16