Journal of Molecular Catalysis B-enzymatic最新文献_第9页

Aspergillus flavipes methionine γ-lyase-dextran conjugates with enhanced structural, proteolytic stability and anticancer efficiency 黄曲霉甲硫氨酸γ-裂解酶-葡聚糖缀合物具有增强的结构、蛋白水解稳定性和抗癌效率

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/J.MOLCATB.2016.11.002

A. El-Sayed, Abdalla E A Hassan, A. Shindia, Shaimaa G. A. Mohamed, M. Sitohy

引用次数: 28

Immobilization of Y. lipolytica lipase and the continuous synthesis of geranyl propionate 脂肪酶的固定化及丙酸香叶醇的连续合成

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.01.019

Jing Tang , Gang Chen , Lu Wang , Ming Miao , Bo Jiang , Biao Feng

{"title":"Immobilization of Y. lipolytica lipase and the continuous synthesis of geranyl propionate","authors":"Jing Tang , Gang Chen , Lu Wang , Ming Miao , Bo Jiang , Biao Feng","doi":"10.1016/j.molcatb.2017.01.019","DOIUrl":"10.1016/j.molcatb.2017.01.019","url":null,"abstract":"<div>In this study, Y. lipolytica lipase LIP2 (Lip2) was immobilized on the macroporous adsorptive resin DA201-C in n-heptane and then used to catalyze the continuous synthesis of geranyl propionate in a continuous stirred tank reactor (CSTR). With the lipase loading of 0.01g/g resin, 25°C and adsorption for 3h, the immobilization efficiency can be up to 98.6% and the synthetic activity of the lipase was 690.8U/g after immobilization, representing an increase of 28.5% compared with the free lipase (synthetic activity 537.2U/g). The immobilized Lip2 was used to generate geranyl propionate in CSTR, the continuous production of geranyl propionate was performed with 3g of immobilized Lip2 at 35°C. At the flow rate of 6mL/h the process can maintain its steady state at least for 12h, which was about three times of the average residence time, and the esterification ratio of 72.8% could be attained. Finally, FT-IR and NMR were used to identify the ester.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S311-S316"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2017.01.019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77360510","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: 4

One-pot stereoselective synthesis of chiral 1, 3-oxathiolane by Trichosporon laibachii lipase: Optimization by response surface methodology integrated a desirability function approach 三叉线虫脂肪酶一锅立体选择性合成手性1,3 -草硫代烷:响应面法及期望函数优化

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2016.07.007

Yuanyuan Zhang, Xin Gao, Caiyun Wang, Zhenkun Zheng, Lulu Wang, Junhong Liu

{"title":"One-pot stereoselective synthesis of chiral 1, 3-oxathiolane by Trichosporon laibachii lipase: Optimization by response surface methodology integrated a desirability function approach","authors":"Yuanyuan Zhang, Xin Gao, Caiyun Wang, Zhenkun Zheng, Lulu Wang, Junhong Liu","doi":"10.1016/j.molcatb.2016.07.007","DOIUrl":"10.1016/j.molcatb.2016.07.007","url":null,"abstract":"<div>The asymmetric synthesis of chiral 1,3-oxathiolan-5-ones has attracted a great deal of attention owing to their broad biological activities and importance as intermediates for a range of useful pharmaceuticals. However, the enantiomeric purity of desired enantiomer was moderate while maintaining high yield. Here, high enantiomerically pure chiral 1,3-oxathiolane intermediate was synthesized by cyclization-acetylation reaction in organic media using immobilized Trichosporon laibachii (T. laibachii) lipase with one-pot process. Response surface methodology (RSM) integrated a desirability function approach was used to study and optimize the reaction conditions. The effects of several reaction parameters (initial water content of reaction medium, lipase amount and reaction temperature) on enantiomeric excess (ee) and the conversion of benzoyl aldehyde (C) were evaluated. The enzyme activity as well as enantioselectivity was markedly influenced by the initial water content of reaction medium and reaction temperature. The maximum overall desirability (D) of 0.958 was achieved at initial water content of 0.46%, lipase amount of 4.58% and reaction temperature 43 <!-->°C. The corresponding maximum ee and C were 94.33% and 97.40%, respectively. A good correlation between the predicted and actual responses showed that the generated model could adequately predict ee and C.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages 27-34"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2016.07.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73711103","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: 11

Characterization of a new lysine decarboxylase from Aliivibrio salmonicida for cadaverine production at alkaline pH 在碱性条件下产尸胺的一种新型赖氨酸脱羧酶的研究

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2016.11.023

Fengyu Kou , Jing Zhao , Jiao Liu , Jie Shen , Qin Ye , Ping Zheng , Zhimin Li , Jibin Sun , Yanhe Ma

{"title":"Characterization of a new lysine decarboxylase from Aliivibrio salmonicida for cadaverine production at alkaline pH","authors":"Fengyu Kou , Jing Zhao , Jiao Liu , Jie Shen , Qin Ye , Ping Zheng , Zhimin Li , Jibin Sun , Yanhe Ma","doi":"10.1016/j.molcatb.2016.11.023","DOIUrl":"10.1016/j.molcatb.2016.11.023","url":null,"abstract":"<div>Lysine decarboxylases (LDCs) catalyze the conversion of l-lysine to cadaverine, a highly attractive building block for bio-based polyamides. Due to economic and environmental concerns, LDCs active at elevated pH are highly desirable. In this study, a new LDC from Aliivibrio salmonicida (AsLdc) was discovered, expressed, and characterized. Compared to the LDCs from Escherichia coli, LdcC and CadA, the latter was frequently used for cadaverine production, the purified AsLdc showed much higher activities at alkaline pH 7.0–8.5, for instance, 205.1U/mg at pH 7.5 with 10μg/mL enzyme, in comparison to 68.3 and 51.5U/mg for CadA and LdcC, respectively. The activities of AsLdc and CadA correlated well with the proportions of decamers at the pH range of 5.0–8.5. AsLdc with a melting temperature of 79°C was more thermostable than CadA (73.6°C). When used for whole-cell biotransformation of l-lysine to cadaverine at pH 7.5, AsLdc completed the transformation within 7h while the CadA did only 82.8%. These results indicate the high potential of the new AsLdc for the industrial production of cadaverine.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S88-S94"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2016.11.023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73458310","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

Computational insights into the oxidation of mono- and 1,4 disubstituted arenes by the Toluene Dioxygenase enzymatic complex 甲苯双加氧酶复合物氧化单和1,4二取代芳烃的计算见解

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.03.003

Ma. Agustina Vila , Diego Umpiérrez , Gustavo Seoane , Sonia Rodríguez , Ignacio Carrera , Nicolás Veiga

{"title":"Computational insights into the oxidation of mono- and 1,4 disubstituted arenes by the Toluene Dioxygenase enzymatic complex","authors":"Ma. Agustina Vila , Diego Umpiérrez , Gustavo Seoane , Sonia Rodríguez , Ignacio Carrera , Nicolás Veiga","doi":"10.1016/j.molcatb.2017.03.003","DOIUrl":"10.1016/j.molcatb.2017.03.003","url":null,"abstract":"<div>Toluene Dioxygenase (TDO) enzymatic complex has been widely used for preparation of enantiopure cis-cyclohexadienediols for synthetic applications. Along the last 30 years, a variety of mono- and di-substituted arenes have been studied as substrates for this enzyme, and some interesting observations have been reported regarding the yield and selectivity of the biotransformation. Nevertheless, none of them has been explained considering the active site’ structural and electronic features. In this work we present the first computational model of TDO’s active site, with a description of its architecture and interactions with the substrate to understand and predict substrate orientation. Our findings indicate that in the O2-free TDO, the iron(II) is stabilized by the coordination of an oxygen atom from the neighboring Gln215 residue. Besides, the active site is comprised by four pockets with different relative affinities for the substrates’ substituents. Monosubstituted arenes adopt a pose in which the alkyl chains maximize the London dispersion interactions with minimal steric clashes, giving an explanation for the observed trend in the benzylic hydroxylation yields. Finally, the computational results allowed us to rationalize the enantiomeric excess of 1,4-disubstituted arenes and the regioselectivity of the dihydroxylation of fluorobenzene. These data were used to develop and validate an affinity index (AI), as a quantitative indicator of the orientation preference for these substrates. This practical and easy-to-use tool can be applied to successfully predict the orientation of the para-disubstituted benzenes into the TDO active site.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S410-S419"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2017.03.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87820126","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

Characterization of the monolignol oxidoreductase AtBBE-like protein 15 L182V for biocatalytic applications 单脂醇氧化还原酶atbe样蛋白15l182v生物催化应用的表征

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2016.10.018

Sabine Pils , Kordula Schnabl , Silvia Wallner , Marko Kljajic , Nina Kupresanin , Rolf Breinbauer , Michael Fuchs , Raquel Rocha , Joerg H. Schrittwieser , Wolfgang Kroutil , Bastian Daniel , Peter Macheroux

{"title":"Characterization of the monolignol oxidoreductase AtBBE-like protein 15 L182V for biocatalytic applications","authors":"Sabine Pils , Kordula Schnabl , Silvia Wallner , Marko Kljajic , Nina Kupresanin , Rolf Breinbauer , Michael Fuchs , Raquel Rocha , Joerg H. Schrittwieser , Wolfgang Kroutil , Bastian Daniel , Peter Macheroux","doi":"10.1016/j.molcatb.2016.10.018","DOIUrl":"10.1016/j.molcatb.2016.10.018","url":null,"abstract":"<div>Monolignol oxidoreductases from the berberine bridge enzyme-like (BBE-like) protein family (pfam 08031) catalyze the oxidation of monolignols to the corresponding aldehydes. In this report, we explore the potential of a monolignol oxidoreductase from Arabidopsis thaliana (AtBBE-like protein 15) as biocatalyst for oxidative reactions. For this study we employed a variant with enhanced reactivity towards oxygen, which was obtained by a single amino acid exchange (L182V). The pH and temperature optima of the purified AtBBE-like protein 15 L182V were determined as well as the tolerance toward organic co-solvents; furthermore the substrate scope was characterized. The enzyme has a temperature optimum of 50°C and retains more than 50% activity between pH 5 and pH 10 within 5min. The enzyme shows increased activity in the presence of various co-solvents (10–50% v/v), including acetonitrile, 2-propanol, 1,4-dioxane, and dimethyl sulfoxide. Primary benzylic and primary or secondary allylic alcohols were accepted as substrates. The enantioselectivity E in the oxidation of secondary alcohols was good to excellent (E>34 to >200).</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S6-S14"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2016.10.018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89309986","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: 6

Specificity of tyrosinase-catalyzed synthesis of theaflavins 酪氨酸酶催化合成茶黄素的特异性

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.03.009

Asako Narai-Kanayama, Aya Kawashima, Yuuka Uchida, Miho Kawamura, Tsutomu Nakayama

{"title":"Specificity of tyrosinase-catalyzed synthesis of theaflavins","authors":"Asako Narai-Kanayama, Aya Kawashima, Yuuka Uchida, Miho Kawamura, Tsutomu Nakayama","doi":"10.1016/j.molcatb.2017.03.009","DOIUrl":"10.1016/j.molcatb.2017.03.009","url":null,"abstract":"<div>This study kinetically characterized the mechanism of the enzymatic synthesis of theaflavins (TFs) from catechins by mushroom tyrosinase (EC 1.14.18.1). In reactions containing one of four catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), and their galloylated forms (ECg and EGCg), they were oxidized by tyrosinase with apparent KM values of 3.78, 5.55, 0.80, and 3.05mM, respectively, and with different consumption rates, of which EC was more than four times higher than those of the others. In reactions with binary combinations of catechins with tyrosinase, the synthesis of TF1 from EC and EGC occurred most efficiently, while the yields of mono- and di-galloylated TFs, TF2A, TF2B, and TF3, were low. Time-dependent changes in concentrations of the reactants suggested that the enzymatic oxidation of catechins and the subsequent non-enzymatic coupling redox reaction between the quinone derived from EC or ECg and the intact pyrogallol-type catechin (EGC or EGCg) proceeded concurrently. The latter reaction induced the rapid decrease of EGC and EGCg and it was remarkable for EGCg. So the efficiency of condensation of a pair of quinones from catechol- and pyrogallol-type catechins is restricted, critically influencing the yield of TFs. Using green tea extracts as mixtures of the four substrate catechins, tyrosinase produced TF1 most abundantly. Furthermore, a remarkable enhancement of production of TF2A and TF2B as well as TF1 was observed, when the initial concentration of EGCg was low. These results suggest that the catechin composition has an impact on yields of TFs.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S452-S458"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2017.03.009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83799091","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: 11

Lipase mediated resolution of cis- and trans-linalool oxide (pyranoid) 脂肪酶介导的顺式和反式芳樟醇氧化物(pyranoid)的分解

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.03.004

Stefano Serra , Davide De Simeis , Elisabetta Brenna

引用次数: 8

Comparative analysis of point mutations on protein COOH terminal near surface and its hydrophobic core provide insights on thermostability of Bacillus Lipase LipJ 通过对蛋白COOH末端近表面及其疏水核心点突变的比较分析，对芽孢杆菌脂肪酶LipJ的热稳定性有了新的认识

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.04.001

Shelly Goomber, Nisha Chopra, Gursimran Kaur Bedi, Jagdeep Kaur

{"title":"Comparative analysis of point mutations on protein COOH terminal near surface and its hydrophobic core provide insights on thermostability of Bacillus Lipase LipJ","authors":"Shelly Goomber, Nisha Chopra, Gursimran Kaur Bedi, Jagdeep Kaur","doi":"10.1016/j.molcatb.2017.04.001","DOIUrl":"10.1016/j.molcatb.2017.04.001","url":null,"abstract":"<div>Amino acid composition, protein conformation, weak interactions are some of the factors determining protein stability. Two point mutants of Bacillus LipJ (Ala81Tyr and Asn166Tyr) were designed and generated for comparison. Residue Ala81 targeted for substitution was buried in protein core with 0% accessibility. On other hand, residue Asn166 at protein <img>COOH terminal was predicted to be located within αF helix near surface. Point variants Ala81Tyr and Asn166Tyr were generated by site directed mutagenesis. In comparison to native protein LipJ, point variant Ala81Tyr was observed to be more thermostable and demonstrated 1.6 times relative activity after 1h exposure at 50°C. However, point variant Asn166Tyr showed dramatic shift in its thermostability, specific activity and substrate specificity pattern compared to wild type LipJ. Asn166Tyr variant was found to remain stable for hours at 50°C. Specific activity of Asn166Tyr was 20% of parent enzyme. Substrate specificity of Asn166Tyr was significantly shifted to fatty acyl chains of shorter lengths. Homolog modelling predicted global vs local structure change to explain molecular basis of differential behavior of point variants Asn166Tyr and Ala81Tyr respectively.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S482-S490"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2017.04.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83992784","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: 1

Insight into the mechanism behind the activation phenomenon of lipase from Thermus thermophilus HB8 in polar organic solvents 研究嗜热热菌HB8脂肪酶在极性有机溶剂中的活化机制

Journal of Molecular Catalysis B-enzymatic Pub Date : 2016-11-01 DOI: 10.1016/j.molcatb.2017.03.002

Hao Cao , Kaili Nie , Haijun Xu , Xin Xiong , Rumen Krastev , Fang Wang , Tianwei Tan , Luo Liu

{"title":"Insight into the mechanism behind the activation phenomenon of lipase from Thermus thermophilus HB8 in polar organic solvents","authors":"Hao Cao , Kaili Nie , Haijun Xu , Xin Xiong , Rumen Krastev , Fang Wang , Tianwei Tan , Luo Liu","doi":"10.1016/j.molcatb.2017.03.002","DOIUrl":"10.1016/j.molcatb.2017.03.002","url":null,"abstract":"<div>A thermophilic lipase from Thermus thermophilus (lipaseTt) was heterologously overexpressed in Escherichia coli BL21(DE3). The tolerance of (lipaseTt) towards polar organic solvents and the associated activation phenomena were investigated. The catalytic efficiency (Kcat/KM) of lipaseTt in 56% DMSO was up to 25.64 times higher than that in phosphate buffer. Molecular dynamic (MD) simulations were carried out to investigate the activation mechanism of the lipaseTt by polar organic solvents. After refining the homology modeling of lipaseTt by using MD-simulation, a new secondary structure in the lid region indicates a rigid structure, corresponding to its nature of thermostability. Subsequently, the loss of a secondary structure of lipaseTt in the presence of polar organic solvent was observed in both MD-simulation and Circular dichroism spectra. The results of MD-simulation demonstrate that the overall structure maintained stable with or without polar organic solvent; however, the lid region was found more flexible in the presence of polar organic solvent. The flexible lid facilitates the substrate to access the catalytic site inside the lipase and the lipase displays enhanced activity in the presence of a polar organic solvent.</div>","PeriodicalId":16416,"journal":{"name":"Journal of Molecular Catalysis B-enzymatic","volume":"133 ","pages":"Pages S400-S409"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcatb.2017.03.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80327596","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: 10