Journal of Molecular Catalysis B: Enzymatic Journal of Molecular Catalysis B: Enzymatic RSS feedThis 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.

The synergism of hot water pretreatment and enzymatic hydrolysis in depolymerization of lignocellulosic content of palm kernel cake
Publication date: Available online 16 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Shuofu Mi, Hongqiang Li, Shuying Li, Yejun Han Palm kernel cake (PKC), mainly composed of mannan, lignin and protein, is abundant renewable resource with commercial value. To develop clean and efficient way for PKC refinery, the method based on the synergism of hot water pretreatment (HWP), steam pretreatment (SP) and enzymatic hydrolysis were developed. HWP of 180°C, 20min and SP of 121°C, 20min showed similar performance for sugar release from PKC. The main saccharides produced from PKC by HWP and SP...
Source: Journal of Molecular Catalysis B: Enzymatic - September 17, 2016 Category: Biochemistry Source Type: research

Towards preparative peroxygenase-catalyzed oxyfunctionalization reactions in organic media
Publication date: Available online 15 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Elena Fernández-Fueyo, Yan Ni, Alvaro Gomez Baraibar, Miguel Alcalde, Lukas M. van Langen, Frank Hollmann The peroxygenase from Agrocybe aegerita (AaeUPO) has been evaluated for stereoselective oxyfunctionalization chemistry under non-aqueous reaction conditions. The stereoselective hydroxylation of ethylbenzene to (R)-1-phenylethanol was performed in neat substrate as reaction medium together with the immobilized biocatalyst and tertBuOOH as oxidant. Stability and activity issues still have to be add...
Source: Journal of Molecular Catalysis B: Enzymatic - September 15, 2016 Category: Biochemistry Source Type: research

A highly efficient immobilized MAS1 lipase for the glycerolysis reaction of n-3 PUFA-rich ethyl esters
This study reported that immobilized MAS1 lipase showed high catalytic efficiency in the production of triacylglycerols (TAG) highly enriched with n-3 polyunsaturated fatty acids (PUFA) by glycerolysis of ethyl esters (EE). Immobilized MAS1 lipase was found to have no regiospecificity and be a more suitable catalyst for the glycerolysis of n-3 PUFA-rich EE compared with other enzymes. Higher TAG content (73.9%) and EE conversion (82%) were obtained by immobilized MAS1 lipase than those by Novozym 435 (29.6% and 54.8%, respectively) and Lipozyme RM IM (10% and 49%, respectively). Besides, the effects of temperature, enzyme ...
Source: Journal of Molecular Catalysis B: Enzymatic - September 14, 2016 Category: Biochemistry Source Type: research

Differential effect of a chemical denaturant on activity and stability of a serine protease in nonaqueous media
Publication date: Available online 14 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Shivcharan Prasad, Villendra S. Negi, Joydev K. Laha, Ipsita Roy With reference to industrial application, reusability of the biocatalyst is an important criterion which determines the cost of the final product. Urea-induced structural perturbation of proteases has led to higher enzymatic activity, especially in nonaqueous media. The mechanism behind this phenomenon has not been investigated in detail. Using the transesterification activity of subtilisin Carlsberg in nonaqueous media as an illustration, ...
Source: Journal of Molecular Catalysis B: Enzymatic - September 14, 2016 Category: Biochemistry Source Type: research

A more polar N-terminal helix releases MBP-tagged Thermus thermophilus proline dehydrogenase from tetramer-polymer self-association
Publication date: Available online 14 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Mieke M.E. Huijbers, Willem J.H. van Berkel Proline dehydrogenase (ProDH) is a ubiquitous flavoenzyme involved in the biosynthesis of L-glutamate. ProDH is of interest for biocatalysis because the protein might be applied in multi-enzyme reactions for the synthesis of structurally complex molecules. We recently demonstrated that the thermotolerant ProDH from Thermus thermophilus (TtProDH) is overproduced in Escherichia coli when using maltose-binding protein (MBP) as a solubility tag. However, MBP-TtProDH ...
Source: Journal of Molecular Catalysis B: Enzymatic - September 14, 2016 Category: Biochemistry Source Type: research

One-pot synthesis of nitrocyclopropane: α-Amylase-catalyzed Michael addition initiated ring-closure sequence reactions
This article presents a one-pot synthesis of nitrocyclopropanes via Michael addition initiated ring-closure sequence reactions of bromonitroalkane to α,β-unsaturated enones. Moderate to favorable yields (55-93%) and certain enantioselectivities were obtained with α-amylase from hog pancreas as the catalyst. This strategy utilizes the unnatural ability of enzymes to provide a convenient and biocatalytic method for green organic synthesis. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - September 13, 2016 Category: Biochemistry Source Type: research

Efficient production of ethyl (R)-4-chloro-3-hydroxybutanoate by a novel alcohol dehydrogenase from Lactobacillus curieae S1L19
In this study, a novel short-chain, NADH-dependent dehydrogenase (LCRIII) from Lactobacillus curieae S1L19 was discovered to exhibit high activity and enantioselectivity in the production of (R)-CHBE by reduction of ethyl 4-chloroacetoacetate (COBE). LCRIII was heterologously overexpressed in Escherichia coli and the protein was purified to homogeneity. Characterization of LCRIII showed broad substrate specificity towards a variety of ketones. In addition, an efficient cofactor regeneration system was constructed by co-expressing LCRIII and glucose dehydrogenase (GDH) in E. coli cells. Up to 1.5M (246.8g/L) COBE could be c...
Source: Journal of Molecular Catalysis B: Enzymatic - September 13, 2016 Category: Biochemistry Source Type: research

Investigation of structural stability and enzymatic activity of glucose oxidase and its subunits
This study provided novel insight to understand the mechanism of enzyme inactivation upon dissociation, which would be useful for rational enzyme design. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - September 12, 2016 Category: Biochemistry Source Type: research

Biocatalytic epoxidation of α-pinene to oxy-derivatives over cross-linked lipase aggregates
Publication date: Available online 12 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Madalina Tudorache, Andreea Gheorghe, Ana S. Viana, Vasile I. Parvulescu Lipase-based cross-linked aggregates were investigated for a non-specific reaction, i.e. the epoxidation of α-pinene to its oxygenated derivatives. The activity of the biocatalysts has been evaluated in a green context, i.e. ethyl acetate as both acetate-supplier and organic solvent with H2O2/UHP/TBHP as oxidant. Screening of the lipase sources indicated Aspergillus niger lipase as the most efficient biocatalyst for this reaction. ...
Source: Journal of Molecular Catalysis B: Enzymatic - September 12, 2016 Category: Biochemistry Source Type: research

A Simple Approach to a Vastly Improved Acetylcholinesterase Activity and Stability at Elevated Temperatures Using Magnetic Microbeads and Poly(N-(3-aminopropyl methacrylamide)) Hydrogel Supports
Publication date: Available online 9 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Lisa C. Shriver-Lake, Paul T. Charles, Andre A. Adams, Jake Fontana, Brett D. Martin The thermal stabilization of enzymes is a critical factor in the development and reliability of enzyme-based processes and functional materials. Using a simple amine coupling approach for enzyme immobilization onto magnetic microbeads, followed by encasement of the beads in a hydrogel, we demonstrate that the thermal stability of the enzyme acetylcholinesterase can be increased dramatically. For example, when free and mi...
Source: Journal of Molecular Catalysis B: Enzymatic - September 9, 2016 Category: Biochemistry Source Type: research

Screening of fungi from the genus Penicillium for production of β- fructofuranosidase and enzymatic synthesis of fructooligosaccharides
Publication date: Available online 6 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): A.K.C. Nascimento, C. Nobre, M.T.H. Cavalcanti, J.A. Teixeira, A.L.F. Porto Eight new isolated fungi of the genus Penicillium were evaluated for β- fructofuranosidase (FFase) production. From these, Penicillium citreonigrum was selected for FFase and fructooligosaccharides (FOS) production. The influence of temperature, yeast extract concentration, pH and fermentation time on the FFase activity when using the whole microorganism were evaluated by 24 and 23 designs. The pH was set at 6.5 and no yeast ext...
Source: Journal of Molecular Catalysis B: Enzymatic - September 6, 2016 Category: Biochemistry Source Type: research

Strategies of covalent immobilization of a recombinant Candida antarctica lipase B on pore-expanded SBA-15 and its application in the kinetic resolution of (R,S)-Phenylethyl acetate
Publication date: Available online 4 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Nathalia S. Rios, Maisa P. Pinheiro, José Cleiton S. dos Santos, Thiago de S. Fonseca, Lara D. Lima, Marcos C. deMattos, Denise M.G. Freire, Ivanildo J. da Silva, Elena Rodríguez-Aguado, Luciana R.B. Gonçalves A recombinant Candida antarctica lipase B expressed in Pichia pastoris (LIPB) was immobilized on pore-expanded SBA-15 previously modified 3-amino-propyltriethoxysilane (APTES) and activated with two bifunctional reagents, glutaraldehyde (GA) or divinylsulfone (DVS), producing the biocatalys...
Source: Journal of Molecular Catalysis B: Enzymatic - September 4, 2016 Category: Biochemistry Source Type: research

Continuous production of chitooligosaccharides by an immobilized enzyme in a dual-reactor system
Publication date: Available online 3 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Paloma Santos-Moriano, John M. Woodley, Jplou Francisco A chitosanolytic activity found in a commercial α-amylase from Bacillus amylolyquefaciens (BAN) was covalently immobilized onto glyoxal agarose beads (25% recovery of activity) and assessed for the continuous production of chitooligosaccharides (COS). The immobilization did not change the reaction profile (with chitotriose and chitobiose as major products, using chitosans of different polymerization and deacetylation degrees), but significantly incre...
Source: Journal of Molecular Catalysis B: Enzymatic - September 3, 2016 Category: Biochemistry Source Type: research

Multi-response behavior of aminosulfonaphthole system
Publication date: Available online 3 September 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Fatih Doğan, İsmet Kaya, Kevser Temizkan Here, we report regioselectively functionalized synthesis, as well as photo physical, electrochemical, and thermal, of a novel water-soluble conjugated polymer. For this purpose, horseradish peroxidase (HRP)-catalyzed polymerization of a multifunctional monomer, 7-amino-4-hydroxy-2-naphthalene sulfonic acid (AHNAPSA) was carried out by using hydrogen peroxide as the oxidant at room temperature for 24h under air. The structure of poly(7-amino-4-hydroxy-2-naphthalen...
Source: Journal of Molecular Catalysis B: Enzymatic - September 3, 2016 Category: Biochemistry Source Type: research

Module recombination and functional integration of oligosaccharide-producing multifunctional amylase
In this study, we investigated the effects of module recombination on the functional integration of OPMA-N. A series of module recombinants of the N-terminal and catalytic modules revealed that the intramolecular, semi-intramolecular and semi-intermolecular interactions of the N-terminal module with two or more catalytic modules enhanced the substrate affinity of the catalytic modules and facilitated the transglycosyl activity and functional integration of the enzyme by mediating positive cooperativity between the catalytic modules. Free N-terminal module alone did not contribute to these effects. Based on the results of t...
Source: Journal of Molecular Catalysis B: Enzymatic - August 31, 2016 Category: Biochemistry Source Type: research