Enzyme Research最新文献_第4页

Extracellular Polyhydroxyalkanoate Depolymerase by Acidovorax sp. DP5 胞外聚羟基烷酸解聚酶(Acidovorax sp. DP5)

Enzyme Research Pub Date : 2015-11-17 DOI: 10.1155/2015/212159

S. Vigneswari, T. S. Lee, K. Bhubalan, A. Amirul

{"title":"Extracellular Polyhydroxyalkanoate Depolymerase by Acidovorax sp. DP5","authors":"S. Vigneswari, T. S. Lee, K. Bhubalan, A. Amirul","doi":"10.1155/2015/212159","DOIUrl":"https://doi.org/10.1155/2015/212159","url":null,"abstract":"Bacteria capable of degrading polyhydroxyalkanoates (PHA) by secreting extracellular depolymerase enzymes were isolated from water and soil samples collected from various environments in Malaysia. A total of 8 potential degraders exhibited clear zones on poly(3-hydroxybutyrate) [P(3HB)] based agar, indicating the presence of extracellular PHA depolymerase. Among the isolates, DP5 exhibited the largest clearing zone with a degradation index of 6.0. The highest degradation activity of P(3HB) was also observed with depolymerase enzyme of DP5 in mineral salt medium containing P(3HB). Based on biochemical characterization and 16S rRNA cloning and sequencing, isolate DP5 was found to belong to the genus Acidovorax and subsequently named as Acidovorax sp. DP5. The highest extracellular depolymerase enzyme activity was achieved when 0.25% (w/v) of P(3HB) and 1 g/L of urea were used as carbon and nitrogen source, respectively, in the culture media. The most suitable assay condition of the depolymerase enzyme in response to pH and temperature was tested. The depolymerase produced by strain Acidovorax sp. DP5 showed high percentage of degradation with P(3HB) films in an alkaline condition with pH 9 and at a temperature of 40°C.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78917110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

Determining the IC50 Values for Vorozole and Letrozole, on a Series of Human Liver Cytochrome P450s, to Help Determine the Binding Site of Vorozole in the Liver 测定Vorozole和来曲唑在一系列人肝细胞色素p450上的IC50值，以帮助确定Vorozole在肝脏中的结合位点

Enzyme Research Pub Date : 2015-11-09 DOI: 10.1155/2015/321820

Lendelle Raymond, Nikita Rayani, Grace Polson, Kylie F. Sikorski, Ailin Lian, Melissa A. VanAlstine-Parris

{"title":"Determining the IC50 Values for Vorozole and Letrozole, on a Series of Human Liver Cytochrome P450s, to Help Determine the Binding Site of Vorozole in the Liver","authors":"Lendelle Raymond, Nikita Rayani, Grace Polson, Kylie F. Sikorski, Ailin Lian, Melissa A. VanAlstine-Parris","doi":"10.1155/2015/321820","DOIUrl":"https://doi.org/10.1155/2015/321820","url":null,"abstract":"Vorozole and letrozole are third-generation aromatase (cytochrome P450 19A1) inhibitors. [11C]-Vorozole can be used as a radiotracer for aromatase in living animals but when administered by IV, it collects in the liver. Pretreatment with letrozole does not affect the binding of vorozole in the liver. In search of finding the protein responsible for the accumulation of vorozole in the liver, fluorometric high-throughput screening assays were used to test the inhibitory capability of vorozole and letrozole on a series of liver cytochrome P450s (CYP1A1, CYP1A2, CYP2A6, and CYP3A4). It was determined that vorozole is a potent inhibitor of CYP1A1 (IC50 = 0.469 μM) and a moderate inhibitor of CYP2A6 and CYP3A4 (IC50 = 24.4 and 98.1 μM, resp.). Letrozole is only a moderate inhibitor of CYP1A1 and CYP2A6 (IC50 = 69.8 and 106 μM) and a very weak inhibitor of CYP3A4 (<10% inhibition at 1 mM). Since CYP3A4 makes up the majority of the CYP content found in the human liver, and vorozole inhibits it moderately well but letrozole does not, CYP3A4 is a good candidate for the protein that [11C]-vorozole is binding to in the liver.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83030966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Lactose Hydrolysis in Milk and Dairy Whey Using Microbial β-Galactosidases 利用微生物β-半乳糖苷酶水解牛奶和乳清中的乳糖

Enzyme Research Pub Date : 2015-10-26 DOI: 10.1155/2015/806240

Michele Dutra Rosolen, Adriano Gennari, G. Volpato, C. F. Volken de Souza

{"title":"Lactose Hydrolysis in Milk and Dairy Whey Using Microbial β-Galactosidases","authors":"Michele Dutra Rosolen, Adriano Gennari, G. Volpato, C. F. Volken de Souza","doi":"10.1155/2015/806240","DOIUrl":"https://doi.org/10.1155/2015/806240","url":null,"abstract":"This work aimed at evaluating the influence of enzyme concentration, temperature, and reaction time in the lactose hydrolysis process in milk, cheese whey, and whey permeate, using two commercial β-galactosidases of microbial origins. We used Aspergillus oryzae (at temperatures of 10 and 55°C) and Kluyveromyces lactis (at temperatures of 10 and 37°C) β-galactosidases, both in 3, 6, and 9 U/mL concentrations. In the temperature of 10°C, the K. lactis β-galactosidase enzyme is more efficient in the milk, cheese whey, and whey permeate lactose hydrolysis when compared to A. oryzae. However, in the enzyme reaction time and concentration conditions evaluated, 100% lactose hydrolysis was not reached using the K. lactis β-galactosidase. The total lactose hydrolysis in whey and permeate was obtained with the A. oryzae enzyme, when using its optimum temperature (55°C), at the end of a 12 h reaction, regardless of the enzyme concentration used. For the lactose present in milk, this result occurred in the concentrations of 6 and 9 U/mL, with the same time and temperature conditions. The studied parameters in the lactose enzymatic hydrolysis are critical for enabling the application of β-galactosidases in the food industry.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91256147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 56

Pseudomonas aeruginosa Exopolyphosphatase Is Also a Polyphosphate: ADP Phosphotransferase 铜绿假单胞菌胞外磷酸酶也是一种多磷酸ADP磷酸转移酶

Enzyme Research Pub Date : 2015-10-21 DOI: 10.1155/2015/404607

Paola Beassoni, L. A. Gallarato, Cristhian Boetsch, M. N. Garrido, Á. T. Lisa

{"title":"Pseudomonas aeruginosa Exopolyphosphatase Is Also a Polyphosphate: ADP Phosphotransferase","authors":"Paola Beassoni, L. A. Gallarato, Cristhian Boetsch, M. N. Garrido, Á. T. Lisa","doi":"10.1155/2015/404607","DOIUrl":"https://doi.org/10.1155/2015/404607","url":null,"abstract":"Pseudomonas aeruginosa exopolyphosphatase (paPpx; EC 3.6.1.11) catalyzes the hydrolysis of polyphosphates (polyP), producing polyPn−1 plus inorganic phosphate (Pi). In a recent work we have shown that paPpx is involved in the pathogenesis of P. aeruginosa. The present study was aimed at performing the biochemical characterization of this enzyme. We found some properties that were already described for E. coli Ppx (ecPpx) but we also discovered new and original characteristics of paPpx: (i) the peptide that connects subdomains II and III is essential for enzyme activity; (ii) NH4 + is an activator of the enzyme and may function at concentrations lower than those of K+; (iii) Zn2+ is also an activator of paPpx and may substitute Mg2+ in the catalytic site; and (iv) paPpx also has phosphotransferase activity, dependent on Mg2+ and capable of producing ATP regardless of the presence or absence of K+ or NH4 + ions. In addition, we detected that the active site responsible for the phosphatase activity is also responsible for the phosphotransferase activity. Through the combination of molecular modeling and docking techniques, we propose a model of the paPpx N-terminal domain in complex with a polyP chain of 7 residues long and a molecule of ADP to explain the phosphotransferase activity.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76940615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis. 来自海洋杆菌EMB8的氯活化嗜盐α-淀粉酶:高效淀粉水解的生产优化和纳米固定化。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-01-18 DOI: 10.1155/2015/859485

Sumit Kumar, S K Khare

{"title":"Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis.","authors":"Sumit Kumar, S K Khare","doi":"10.1155/2015/859485","DOIUrl":"https://doi.org/10.1155/2015/859485","url":null,"abstract":"Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by \"one-at-a-time approach.\" Starch was found to be the best carbon source at 5% (w/v) concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v) NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL). α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/859485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33373589","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: 23

An efficient and improved methodology for the screening of industrially valuable xylano-pectino-cellulolytic microbes. 筛选具有工业价值的木聚糖-果胶-纤维素分解微生物的有效改进方法。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-01-26 DOI: 10.1155/2015/725281

Avtar Singh, Amanjot Kaur, Anita Dua, Ritu Mahajan

{"title":"An efficient and improved methodology for the screening of industrially valuable xylano-pectino-cellulolytic microbes.","authors":"Avtar Singh, Amanjot Kaur, Anita Dua, Ritu Mahajan","doi":"10.1155/2015/725281","DOIUrl":"https://doi.org/10.1155/2015/725281","url":null,"abstract":"Xylano-pectino-cellulolytic enzymes are valuable enzymes of the industrial sector. In our earlier study, we have reported a novel and cost effective methodology for the qualitative screening of cellulase-free xylano-pectinolytic microorganisms by replacing the commercial, highly expensive substrates with agricultural residues, but the microorganisms with xylanolytic, pectinolytic, cellulolytic, xylano-pectinolytic, xylano-cellulolytic, pectino-cellulolytic, and xylano-pectino-cellulolytic potential were obtained. The probability of getting the desired combination was low, so efforts were made to further improve this cost effective methodology for obtaining the high yield of the microbes capable of producing desired combination of enzymes. By inclusion of multiple enrichment steps in sequence, using only practically low cost substrates and without any nutrient media till primary screening stage, this improved novel protocol for screening gave only the desired microorganisms with xylano-pectino-cellulolytic activity. Using this rapid, efficient, cost effective, and improved methodology, microbes with required combination of enzymes can be obtained and the probability of getting the desired microorganisms is cent percent. This is the first report presenting the methodology for the isolation of xylano-pectino-cellulolytic positive microorganisms at low cost and consuming less time. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/725281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33393832","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: 23

Effect of Diffusion on Discoloration of Congo Red by Alginate Entrapped Turnip (Brassica rapa) Peroxidase. 海藻酸盐包埋芜菁过氧化物酶扩散对刚果红变色的影响。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-02-05 DOI: 10.1155/2015/575618

Afaf Ahmedi, Mahmoud Abouseoud, Amrane Abdeltif, Couvert Annabelle

{"title":"Effect of Diffusion on Discoloration of Congo Red by Alginate Entrapped Turnip (Brassica rapa) Peroxidase.","authors":"Afaf Ahmedi, Mahmoud Abouseoud, Amrane Abdeltif, Couvert Annabelle","doi":"10.1155/2015/575618","DOIUrl":"https://doi.org/10.1155/2015/575618","url":null,"abstract":"Enzymatic discoloration of the diazo dye, Congo red (CR), by immobilized plant peroxidase from turnip \"Brassica rapa\" is investigated. Partially purified turnip peroxidase (TP) was immobilized by entrapment in spherical particles of calcium alginate and was assayed for the discoloration of aqueous CR solution. Experimental data revealed that pH, reaction time, temperature, colorant, and H2O2 concentration play a significant role in dye degradation. Maximum CR removal was found at pH 2.0, constant temperature of 40°C in the presence of 10 mM H2O2, and 180 mg/L of CR. More than 94% of CR was removed by alginate immobilized TP after 1 h of incubation in a batch process under optimal conditions. About 74% removal efficiency was retained after four recycles. Diffusional limitations in alginate beads such as effectiveness factor η, Thiele modulus Φ, and effective diffusion coefficients (D e ) of Congo red were predicted assuming a first-order biodegradation kinetic. Results showed that intraparticle diffusion resistance has a significant effect on the CR biodegradation rate. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/575618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33097579","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: 11

Immobilization of Papain on Chitin and Chitosan and Recycling of Soluble Enzyme for Deflocculation of Saccharomyces cerevisiae from Bioethanol Distilleries. 几丁质和壳聚糖对木瓜蛋白酶的固定化及可溶酶的回收用于生物乙醇蒸馏的酿酒酵母菌脱絮。

Enzyme Research Pub Date : 2015-01-01 DOI: 10.1155/2015/573721

Douglas Fernandes Silva, Henrique Rosa, Ana Flavia Azevedo Carvalho, Pedro Oliva-Neto

{"title":"Immobilization of Papain on Chitin and Chitosan and Recycling of Soluble Enzyme for Deflocculation of Saccharomyces cerevisiae from Bioethanol Distilleries.","authors":"Douglas Fernandes Silva, Henrique Rosa, Ana Flavia Azevedo Carvalho, Pedro Oliva-Neto","doi":"10.1155/2015/573721","DOIUrl":"https://doi.org/10.1155/2015/573721","url":null,"abstract":"Yeast flocculation (Saccharomyces cerevisiae) is one of the most important problems in fuel ethanol production. Yeast flocculation causes operational difficulties and increase in the ethanol cost. Proteolytic enzymes can solve this problem since it does not depend on these changes. The recycling of soluble papain and the immobilization of this enzyme on chitin or chitosan were studied. Some cross-linking agents were evaluated in the action of proteolytic activity of papain. The glutaraldehyde (0.1-10% w·v(-1)), polyethyleneimine (0.5% v·v(-1)), and tripolyphosphate (1-10% w·v(-1)) inactivated the enzyme in this range, respectively. Glutaraldehyde inhibited all treatments of papain immobilization. The chitosan cross-linked with TPP in 5 h of reaction showed the yield of active immobilized enzyme of 15.7% and 6.07% in chitosan treated with 0.1% PEI. Although these immobilizations have been possible, these levels have not been enough to cause deflocculation of yeast cells. Free enzyme was efficient for yeast deflocculation in dosages of 3 to 4 g·L(-1). Recycling of soluble papain by centrifugation was effective for 14 cycles with yeast suspension in time perfectly compatible to industrial conditions. The reuse of proteases applied after yeast suspension by additional yeast centrifugation could be an alternative to cost reduction of these enzymes. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/573721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33010457","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: 19

Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity. 将人体红细胞中的乙酰胆碱酯酶作为铅诱导神经毒性的替代生物标志物

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-10-22 DOI: 10.1155/2015/370705

Vivek Kumar Gupta, Rajnish Pal, Nikhat Jamal Siddiqi, Bechan Sharma

{"title":"Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity.","authors":"Vivek Kumar Gupta, Rajnish Pal, Nikhat Jamal Siddiqi, Bechan Sharma","doi":"10.1155/2015/370705","DOIUrl":"10.1155/2015/370705","url":null,"abstract":"Lead induced neurotoxicity in the people engaged in different occupations has received wide attention but very little studies have been carried out to monitor occupational neurotoxicity directly due to lead exposure using biochemical methods. In the present paper an endeavour has been made in order to assess the lead mediated neurotoxicity by in vitro assay of the activity of acetylcholinesterase (AChE) from human erythrocytes in presence of different concentrations of lead. The results suggested that the activity of this enzyme was localized in membrane bound fraction and it was found to be highly stable up to 30 days when stored at -20°C in phosphate buffer (50 mM, pH 7.4) containing 0.2% Triton X-100. The erythrocyte's AChE exhibited K m for acetylcholinesterase to be 0.1 mM. Lead caused sharp inhibition of the enzyme and its IC50 value was computed to be 1.34 mM. The inhibition of the enzyme by lead was found to be of uncompetitive type (K i value, 3.6 mM) which negatively influenced both the V max and the enzyme-substrate binding affinity. Taken together, these results indicate that AChE from human erythrocytes could be exploited as a surrogate biomarker of lead induced neurotoxicity particularly in the people occupationally exposed to lead. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4633554/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81142955","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

Improved Enzyme Catalytic Characteristics upon Glutaraldehyde Cross-Linking of Alginate Entrapped Xylanase Isolated from Aspergillus flavus MTCC 9390. 黄曲霉MTCC 9390海藻酸包埋木聚糖酶戊二醛交联催化性能的改进

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-08-12 DOI: 10.1155/2015/210784

Bharat Bhushan, Ajay Pal, Veena Jain

引用次数: 49