Journal of Molecular Catalysis B: Enzymatic This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Novel enzyme/exfoliated bentonite nanohybrids as highly efficient and recyclable biocatalysts in hydrolytic reaction
Publication date: Available online 29 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Jie Cao, Yimin Li, Ni Tu, Ying Lv, Qinqin Chen, Huaping Dong Bentonite exfoliation liberated the interlayer surface with large area for immobilization of enzyme at high enzyme loading. Upon the electrostatic attraction between positively charged bovine pancreatic lipase (BPL), Yarrawia lipolytica lipase (YLL), trypsin and negatively charged surface of unilaminar bentonite, three nanohybrids with a stably card-like structure named as BPL-B, YLL-B and TB were facilely produced. These nanohybrids showe...
Source: Journal of Molecular Catalysis B: Enzymatic - July 3, 2016 Category: Biochemistry Source Type: research

Kinetic investigations of 6-phosphogluconate dehydrogenase confined in mesoporous silica
In this study 6-phospogluconate dehydrogenase (6PGDH) from Geobacillus stearothermophilus was adsorbed onto the inner surface of mesoporous cellular siliceous foams (MCF). To initiate different attractive interactions between the surface of 6PGDH and the respective silica hosts, the pore walls of the MCFs have been functionalized with alkyl and aminoalkyl residues consisting of different chain lengths (–C3, –C5, –C7, –C11 and –C3NH2, –C5NH2, –C7NH2, –C11NH2). Each modified MCF has been analyzed by nitrogen physisorption, thermal analysis as well as zeta potential titrations. Enzyme uptakes, loading densitie...
Source: Journal of Molecular Catalysis B: Enzymatic - June 17, 2016 Category: Biochemistry Source Type: research

Enzyme-substrate matching in biocatalysis: in silico studies to predict substrate preference of ten putative ene-reductases from Mucor circinelloides MUT44.
Publication date: Available online 16 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Gianluca Catucci, Alice Romagnolo, Federica Spina, Giovanna Cristina Varese, Gianfranco Gilardi, Giovanna Di Nardo Ene-reductases are flavoproteins able to catalyse the reduction of carbon-carbon double bonds with many potential applications in biocatalysis. The fungus Mucor circinelloides MUT44 has high ene-reductase activity when grown in the presence of substrates carrying different electron-withdrawing groups. Genome sequencing revealed the presence of ten putative genes coding for ene-reductase...
Source: Journal of Molecular Catalysis B: Enzymatic - June 15, 2016 Category: Biochemistry Source Type: research

Enzymatic production of prebiotic fructo‐oligosteviol glycosides
Publication date: Available online 15 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Sebastian C. Spohner, Peter Czermak Fructo-oligosaccharides are low-caloric sweeteners with 30–50% of the sweetness of sucrose. They are also used as functional food ingredients due to their prebiotic properties, i.e. they stimulate the growth and activity of lactobacilli and bifidobacteria in the digestive tract. Such compounds are normally extracted from chicory, but they can also be produced enzymatically from sucrose using fructosyltransferases. Steviol glycosides are naturally sweet constituents of S...
Source: Journal of Molecular Catalysis B: Enzymatic - June 14, 2016 Category: Biochemistry Source Type: research

Cloning, overexpression and characterization of a xylanase gene from a novel Streptomyces rameus L2001 in Pichia pastoris
Publication date: Available online 15 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Ran Yang, Jinchun Li, Chao Teng, Xiuting Li A novel GC-rich xylanase gene named xynA from Streptomyces rameus L2001 was cloned by high-efficiency thermal asymmetric interlaced PCR. The open reading frame of the cloned gene contained 672bp and encoded 223 amino acid residues with a calculated molecular mass of 24.5kDa. The recombinant xylanase (XynA) was scaled up in a 2.5L fermenter using BSM and BMMY medium; the highest enzyme activity, 13626U/mL, was obtained from BSM. This is the first report of high...
Source: Journal of Molecular Catalysis B: Enzymatic - June 14, 2016 Category: Biochemistry Source Type: research

Characterization of a recombinant multifunctional glycoside hydrolase family 3 β-xylosidase/α-L-arabinofuranosidase/β-glucosidase from Cellulosimicrobium cellulans sp. 21
Publication date: Available online 10 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Ye Yuan, Yanbo Hu, Han Zhang, Jiayi Leng, Fan Li, Xuesong Zhao, Juan Gao, Yifa Zhou A multifunctional β-xylosidase/α-L-arabinofuranosidase/β-glucosidase gene (ccxyl3a) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp.21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95kDa. With p-nitrophenyl-β-D-xyloside (pNPβXyl) as a substrate, the purified protein presented an optimal...
Source: Journal of Molecular Catalysis B: Enzymatic - June 9, 2016 Category: Biochemistry Source Type: research

Organic solvent-tolerant, cold-adapted lipases PML and LipS exhibit increased conformational flexibility in polar organic solvents
Publication date: Available online 8 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Vinaykumar Dachuri, Jerusha Boyineni, Sora Choi, Hye-Shin Chung, Sei-Heon Jang, ChangWoo Lee Organic solvent-tolerant enzymes are generally stable in organic solvents, but the conformational changes of the enzymes in organic solvents have not been well studied. As cold-adapted enzymes exhibit increased conformational flexibility as compared with their mesophilic counterparts, we investigated the effects of polar organic solvents (dimethyl sulfoxide, methanol, and ethanol) on the flexibility and stabi...
Source: Journal of Molecular Catalysis B: Enzymatic - June 8, 2016 Category: Biochemistry Source Type: research

SIMULTANEOUS SINGLE-STEP IMMOBILIZATION OF Candida antarctica LIPASE B AND INCORPORATION OF MAGNETIC NANOPARTICLES ON POLY(UREA-URETHANE) NANOPARTICLES BY INTERFACIAL MINIEMULSION POLYMERIZATION
Publication date: Available online 7 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Viviane Chiaradia, Alexsandra Valério, Débora de Oliveira, Pedro H.H. Araújo, Claudia Sayer In this work Candida antarctica lipase B (E.C: 3.1.1.3), was immobilized on magnetic poly(urea-urethane) nanoparticles (MNPs-PUU) in a single-step during the interfacial miniemulsion polymerization. Transmission electron microscopy images showed the morphology of synthesized magnetic nanoparticles encapsulated in poly(urea-urethane) nanoparticles and fluorescence microscopy images confirmed the enzyme immobil...
Source: Journal of Molecular Catalysis B: Enzymatic - June 7, 2016 Category: Biochemistry Source Type: research

Effect of hemicellulolytic enzymes to improve sugarcane bagasse saccharification and xylooligosaccharides production
In this study, only two hemicelulases, the endo-1,4-xylanases (GH11) from Penicillium funiculosum (XynC11/CAC15487) and the feruloyl esterase (CE1) from Clostridium thermocellum (CtFAE/ATCC27405), effectively broke-down hemicellulose from pretreated sugarcane bagasse (up to 65%), along with the production of xylooligosaccharides (XOS). Our results also demonstrated that GH11 and CE1 can improve biomass saccharification by cellulases. Treatment with these two enzymes followed by a commercial cellulase cocktail (Accellerase®1500) increased saccharification of pretreated lignocellulose by 24%. Collectively, our data contribu...
Source: Journal of Molecular Catalysis B: Enzymatic - June 6, 2016 Category: Biochemistry Source Type: research

Papain-catalyzed aldol reaction for the synthesis of trifluoromethyl carbinol derivatives
Publication date: Available online 3 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Jun-Tao Guo, Yang Xiang, Zhi Guan, Yan-Hong He Papain from Carica papaya demonstrated catalytic promiscuity was first discovered to catalyze the synthesis of trifluoromethyl carbinol derivatives via aldol reaction between α,α,α-trifluoromethyl ketones and aliphatic ketones in a mixed solvent of DMF and water. The best results of the corresponding aldol products with up to 99% yield and 30% ee were achieved. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - June 6, 2016 Category: Biochemistry Source Type: research

Biochemical Properties of a New Nitrile Reductase Cloned from Pectobacterium carotovorum
Publication date: Available online 4 June 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Min Li, Zheng Zhou, Zhi-Jun Zhang, Hui-Lei Yu, Jian-He Xu Nitrile reductase is a newly discovered enzyme class that can catalyze the reduction of nitriles directly to amines, a very important reaction in synthetic organic chemistry. However, little progress has been made towards the application of this biocatalysis reaction for organic synthesis since the initial discovery of nitrile reductase for over ten years. One of the potential reasons may be due to the lack of structural information and biochemi...
Source: Journal of Molecular Catalysis B: Enzymatic - June 6, 2016 Category: Biochemistry Source Type: research

Enzymatic deglycosylation of flavonoids in deep eutectic solvents-aqueous mixtures: paving the way for sustainable flavonoid chemistry
Publication date: August 2016 Source:Journal of Molecular Catalysis B: Enzymatic, Volume 130 Author(s): Gisela Weiz, Lucas Braun, Rosana Lopez, Pablo Domínguez de María, Javier D. Breccia The low solubility of glycosylated flavonoids represents a hurdle to conduct efficient enzymatic deglycosylations in aqueous media. To overcome this drawback, environmentally-unfriendly dimethylsulfoxide (DMSO) is typically used as co-solvent. Using a specific diglycosidase from Acremonium sp. DSM24697 for the deglycosylation of the rutinosylated flavonoid (hesperidin) as model reaction, this communication explores the use...
Source: Journal of Molecular Catalysis B: Enzymatic - May 27, 2016 Category: Biochemistry Source Type: research

Biocatalytic behavior of a new Aspergillus niger whole-cell biocatalyst with high operational stability during the synthesis of green biosolvent isopropyl esters
Publication date: Available online 26 May 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Zhiyou Pan, Shen Jin, Xi Zhang, Suiping Zheng, Shuangyan Han, Li Pan, Lin Ying Using microbial cell-surface displayed enzymes to produce chemicals is a promising green chemistry procedure, but few studies evaluated filamentous fungi cell-surface display systems. Here, a novel Aspergillus niger whole-cell biocatalyst with excellent operational stability was constructed using a heterologous anchor protein, and the details about its practical catalytic characteristics during the synthesis of green bio...
Source: Journal of Molecular Catalysis B: Enzymatic - May 25, 2016 Category: Biochemistry Source Type: research

Synthesis of ß-(2-6)-linked fructan with a partially purified levansucrase from Bacillus subtilis
Publication date: Available online 24 May 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Artur Szwengiel, Kamila Goderskaa, Małgorzata Gumienna Levansucrase (EC 2.4.1.10) forms levan, a fructose homopolymer. The efficient production of fructans is affected by a few factors, including substrate concentration, temperature, pH, and the presence of enzyme cofactors. Conditions were thus optimized for the partially purified levansucrase from Bacillus subtilis DSM 347. The ratio of transferase to hydrolytic activity was determined by the LC-MS method. The synthesized fructan was analysed by two-dim...
Source: Journal of Molecular Catalysis B: Enzymatic - May 24, 2016 Category: Biochemistry Source Type: research

Catalytic mechanism of human glyoxalase I studied by quantum-mechanical cluster calculations
Publication date: Available online 24 May 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Sonia Jafari, Ulf Ryde, Mehdi Irani Density functional theory has been used to study the mechanism and stereospecificity of the catalytic reaction of human glyoxalase I. We used the quantum mechanical cluster method to model the enzyme active site. Glyoxalase I accepts both enantiomers of the hemithioacetal between methylglyoxal and glutathione and converts them to the S-D enantiomer of lactoylglutathione. We have compared several previously suggested or alternative reaction mechanisms for both substrates ...
Source: Journal of Molecular Catalysis B: Enzymatic - May 24, 2016 Category: Biochemistry Source Type: research