Journal of Molecular Catalysis B Enzymatic (J MOL CATAL B-ENZYM)

Publisher: Elsevier

Journal description

The journal is an international forum devoted to research and developments in the applications of whole-cell and cell-free enzymes as catalysts in organic synthesis. Emphasis is focused on mechanistic and synthetic aspects of the biocatalytic transformation.Papers deal with the following topics; Industrial applications of enzymatic processes, e.g. in fine chemical synthesis; Chemo-, regio- and enantioselective transformations; Screening for biocatalysts; Integration of biocatalytic and chemical steps in organic syntheses; Novel biocatalysts, e.g. enzymes from extremophiles and catalytic antibodies; Enzyme immobilization and stabilization, particularly in non-conventional media; Bioprocess engineering aspects, e.g. membrane bioreactors; Improvement of catalytic performance of enzymes, e.g. by protein engineering or chemical modification; Structural studies, including computer simulation, relating to substrate specificity and reaction selectivity; Biomimetic studies related to enzymatic transformations.

Current impact factor: 2.75

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 2.745
2012 Impact Factor 2.823
2011 Impact Factor 2.735
2010 Impact Factor 2.33
2009 Impact Factor 2.4
2008 Impact Factor 2.015
2007 Impact Factor 1.973
2006 Impact Factor 2.149
2005 Impact Factor 1.685
2004 Impact Factor 1.547
2003 Impact Factor 1.475
2002 Impact Factor 1.451
2001 Impact Factor 1.408
2000 Impact Factor 1.448
1999 Impact Factor 1.126
1998 Impact Factor 1.386
1997 Impact Factor 1.132

Impact factor over time

Impact factor
Year

Additional details

5-year impact 2.81
Cited half-life 5.60
Immediacy index 0.54
Eigenfactor 0.01
Article influence 0.60
Website Journal of Molecular Catalysis B: Enzymatic website
Other titles Journal of molecular catalysis
ISSN 1873-3158
OCLC 39177340
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Elsevier

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Pre-print allowed on any website or open access repository
    • Voluntary deposit by author of authors post-print allowed on authors' personal website, arXiv.org or institutions open scholarly website including Institutional Repository, without embargo, where there is not a policy or mandate
    • Deposit due to Funding Body, Institutional and Governmental policy or mandate only allowed where separate agreement between repository and the publisher exists.
    • Permitted deposit due to Funding Body, Institutional and Governmental policy or mandate, may be required to comply with embargo periods of 12 months to 48 months .
    • Set statement to accompany deposit
    • Published source must be acknowledged
    • Must link to journal home page or articles' DOI
    • Publisher's version/PDF cannot be used
    • Articles in some journals can be made Open Access on payment of additional charge
    • NIH Authors articles will be submitted to PubMed Central after 12 months
    • Publisher last contacted on 18/10/2013
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Ketose 3-epimerase displayed an important role in not only the cyclic monosaccharides bioconversion strategy, named Izumoring, but also in the industrial biological production of D-psicose, a novel low-calorie rare sugar widely used in food and medical industries. Since the non-enzymatic side reactions could be reduced in acid conditions, slightly acidic pH optimum is one of the main issues for biological production of D-psicose. In this study, we first characterized an acidic ketose 3-epimerase, the recombinant D-psicose 3-epimerase (DPEase) from Dorea sp. CAG317. The protein exhibited high amino acid sequence identity with other reported DPEases, and was determined as a homotetramer with subunit molecular weight approximately 33 kDa, which was the same as other reported findings. The recombinant DPEase was a metal-dependent enzyme with the optimum metal cofactor as Co2+. In presence of 1 mM of Co2+, the enzyme displayed the maximal activity as 803 U/mg at pH 6.0 and 70 °C. The catalytic efficiency (kcat/Km) was measured to be 412 and 199 mM-1 min-1 toward D-psicose and D-fructose, respectively. The equilibrium ratio between D-fructose and D-psicose was approximately 30:70, and the elevated temperature did not significantly shift the equilibrium toward D-psicose. Compared to other reported DPEases, the recombinant Dorea sp. DPEase displayed significantly higher specific activity at acidic pHs and remarkably higher productivity of D-psicose at pH 6.0, indicating that it was appropriate for use as a new source of D-psicose producing enzyme.
    Journal of Molecular Catalysis B Enzymatic 07/2015; DOI:10.1016/j.molcatb.2015.05.018
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    ABSTRACT: Enzymatic production of biodiesel from canola oil using self-made covalently immobilized lipase from Candida antarctica (CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) on epoxy-functionalized silica as low cost catalyst was investigated. In this optimization study, the effect of water, t-butanol and water adsorbent content on the yield of fatty acid methyl ester (FAME) was considered. Complete conversion to FAMEs was achieved under optimum conditions for CALB immobilized on epoxy-functionalized silica (Silica-CALB); 30% w/w t-butanol by substrate weight, reaction time of 96 h, 50 °C and molar ratio of methanol to oil 3:1, which was added to the reaction mixture in three steps. In general by adding t-butanol to the reaction medium, the conversion of oil to FAME increased for RML immobilized on epoxy-functionalized silica (Silica-RML) and 50 wt% t-butanol by substrate weight gave the best yield. TLL immobilized on epoxy-functionalized silica (Silica-TLL) reach to 100% yield at 10% t-butanol. Water suppresses the methanolysis reaction catalyzed by silica-CALB but significantly increased FAME yield for silica-TLL and silica-RML. It was observed that at high water adsorbent amounts (more than 55% w/w), conversion to FAME decreased possibly due to mass transfer limitation. The immobilized TLL was quite stable and can be reused for 16 cycles without significant loss in activity (95%). The immobilized preparations of RML and CALB also presented a good reusability, keeping 85% of their initial activities after 16 cycles of the reaction.
    Journal of Molecular Catalysis B Enzymatic 07/2015; DOI:10.1016/j.molcatb.2015.06.014
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    ABSTRACT: A novel β-glucosidase gene (ccbgl1a) was cloned from the ginsenosides-transforming strain Cellulosimicrobium cellulans sp.21. This enzyme was overexpressed in Escherichia coli, the recombinant β-glucosidase (CcBgl1A) containing N-terminal His-tag was sufficiently purified by nickel metal affinity chromatography with purification factor of 1.9-fold and specific activity of 31.5 U/mg. The molecular mass of recombinant CcBgl1A was estimated to be approximately 46 kDa. CcBgl1A exhibited optimal activity at 35oC and pH 5.5. However, above 40oC, the enzyme stability significantly decreased. The enzyme showed high bioconversion ability on protopanaxadiol-type ginsenosides mixture (PPDGM), which could hydrolyze the outer C-3 glucose moieties of ginsenosides Rb1, Rb2, Rc and Rd into the rare ginsenosides Gypenoside XVII (Gyp XVII), compound O, ginsenoside Mb and ginsenoside F2. Scaled-up production using 1 g of the PPDGM resulted in 292 mg Gyp XVII, 134 mg CO, 184 mg Mb, and 62 mg F2, with chromatographic purities. These results suggest that CcBgl1A would be potentially useful in the preparation of pharmacologically active minor ginsenosides Gyp XVII, CO, Mb and F2.
    Journal of Molecular Catalysis B Enzymatic 07/2015; DOI:10.1016/j.molcatb.2015.06.015
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    ABSTRACT: Galactose oxidase (EC 1.1.3.9) is a single copper metalloenzyme, having a molecular weight of 65-68 kDa. Galactose oxidase catalyzes the oxidation of primary alcohols to corresponding aldehydes with strict regioselectivity, and the selectivity is high for the galactose C-6 primary hydroxyl group. The oxidation of alcohols to carbonyl compounds is one of the most important reactions in synthetic chemistry, thus enzymatic biocatalysis requiring only molecular oxygen as an oxidant is a valuable alternative to chemical reagents.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.006
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    ABSTRACT: In this study, a novel process for enzymatic production of agmatine from L-arginine using recombinant arginine decarboxylase (ADC) was established. The speA gene encoding ADC was expressed in Escherichia coli BL21 (DE3) in a soluble and active form, and recombinant ADC exhibited a maximum specific activity of 0.53 U mg-1 following optimization of culture conditions using an orthogonal array experiment. Up to 14.3 g l−1 of agmatine was obtained from 20 g l−1 of L-arginine in 6 h under optimum conditions (3.5 g l−1 intact cells, 4 mM Mg2+, 30 mM pyridoxal-5′-phosphate (PLP), pH 7, 37 °C). This represents a significant improvement in a method for production of agmatine.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.008
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    ABSTRACT: A maltose-forming α-amylase was purified from the culture supernatant of Lactobacillus plantarum S21 cultivated on starch. The enzyme is a monomer with a molecular mass of 95 kDa, its activity is Ca2+-independent, and the optimum of amylase activity was found at pH 5.0 and 45 °C. A remarkable property of the enzyme is its stability over the broad pH range of 4.0 to 8.0 at 37 °C, where 80-95% of its activity was retained for 12 days and 70-75% was retained for 30 days. The main hydrolysis products from starch, amylose, amylopectin as well as glycogen were maltose (60%) and glucose (38%). The ORF of 2,733 bp was confirmed to be an amylase-encoding gene by sequence comparison. The amylase gene encodes a protein of 910 amino acids including a signal peptide sequence. Both the nucleotide and amino acids sequence shared more than 96% identity with the α-amylases from L. plantarum A6, L. manihotivorans LMG18010 and L. amylovorus NRRL B-4540, yet the properties of the enzyme showed some distinct differences to these latter α-amylases and other lactobacillal α-amylases.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.010
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    ABSTRACT: The endoglucanase gene EG5B of 1611 bp with a predicted molecular weight of 58.6 kDa from Paenibacillus sp. IHB B 3084 was cloned and expressed in Escherichia coli BL21(DE3). The analysis of deduced amino acid sequence revealed a modular structure of the endoglucanase EG5B with an N-terminal catalytic domain of glycosyl hydrolase family 5 and a C-terminal carbohydrate-binding module of family 3. The purified enzyme showed high hydrolytic activity on carboxymethylcellulose, low activity on p-nitrophenyl β-D-cellobioside, avicel and filter paper, and no activity on microcrystalline cellulose, p-nitrophenyl β-D-glucoside, cellobiose and salicin as substrates. The enzyme was mild-alkaline active with optimum activity at pH 7-8 and stable over broad pH range. The temperature optimum was at 50 °C with >50% activity over 30-60 °C. The enzyme stability with >63% residual activity towards non-ionic and anionic surfactants and commercial detergents suggested its compatibility as an additive to detergents.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.009
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    ABSTRACT: A glycoside hydrolase family protein, designated AmyASS, from the marine fish pathogen Aeromonas salmonicida ssp. salmonicida A449 was expressed in Escherichia coli as inclusion bodies, which was renatured by a simple stepwise dialysis. AmyASS has more than 50% identity with many putative glycosidases. Based on the mode of hydrolytic action and the type of substrates, AmyASS was clearly defined as a saccharifying-type α-amylase, which is the third extracellular α-amylase of A. salmonicida ssp. salmonicida. AmyASS showed a raw starch digesting ability, and the specific activity toward raw rice starch (23.5±1.6 U mg-1) was much higher than that toward raw wheat starch and raw mung starch. The catalytic region of AmyASS has 50% identity with the raw starch-degrading α-amylase AmyP, whereas AmyASS does not possess a starch-binding domain (SBD). AmyASS was optimally active at pH 6.0 and 40 °C toward soluble starch and at pH 7.0 and 40 °C toward raw starch. The enzyme exhibited stability under acidic (pH 6.0) conditions, while the activity decreased rapidly under neutral (pH 7.0) conditions. The AmyASS activity was stimulated by Ca2+, Co2+ and Cu2+.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.005
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    ABSTRACT: A water-soluble iron(III)-tetrakis(p-sulfonatephenyl)porphyrin (FeTPPS) complex was loaded on cyclodextrin polymers (CDPs) by forming inclusion complexes. The amount of the loaded FeTPPS for γ-CDP was much larger than the corresponding values for α- and β-CDPs. All of the prepared FeTPPS/CDPs showed catalytic activities for the oxidative degradation of TBBPA at pH 8. Although the turnover frequency (TOF) value for the FeTPPS/α-CDP catalyst was the largest among all the catalysts tested, the FeTPPS/γ-CDP catalyst was inhibited less in the presence of humic acid, which is a major component of landfill leachates. During a 4-h incubation period, 4–8% of the loaded FeTPPS was eluted from the FeTPPS/CDP catalysts, and their efficiencies for the degradation of TBBPA and debromination decreased with increasing recycle times for FeTPPS/α-CDP and FeTPPS/β-CDP. However, the decreases in efficiency for the oxidation of TBBPA were smaller in the case of the FeTPPS/γ-CDP catalyst. In conclusion, the FeTPPS/γ-CDP catalyst performed at a much higher level compared to the FeTPPS/α-CDP and FeTPPS/β-CDP catalysts, in terms of inhibition by coexisting substances and reusability.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.002
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    ABSTRACT: The lipase of Serratia marcescens (SML) with 614 amino acid residues belongs to the lipase family I.3 has an important pharmaceutical application in production of chiral precursors. Like other members of this family, the SML consists of the N-catalytic domain (α/β) that contains the active-site residues and the C-terminal domain including the two parallel β-roll domains, the first and second β-roll. The repetitive sequences, a nine-residue sequence motif (GGXGXDXUX), in SML are somewhat degenerated as well as are not consecutive. The parallel β-roll domains separated by a 72 residues spacer from each other. The importance of these repetitive sequences is not yet fully understood. In the present investigation, as an approach, a C-terminally truncated (∼13 kD) SML was generated using PCR-based site-directed mutagenesis method (designated SML-Δ128). Both wild-type and truncated forms of SML were constructed, overexpressed in E. coli without Lip-system and purified by affinity chromatography on the Ni-NTA system. Kinetic parameters and circular dichroism (CD) spectra were determined and compared. The SML-Δ128 showed an approximately 3.7-fold increase in the turnover rate (kcat), relative to that of the full-length enzyme. In conclusion, this report demonstrates that the SML could tolerate extensive modification in the C-terminal extreme of the protein, as deletion of the C-terminal region (∼13 kDa), consisting of several tandem repeats of glycine-rich and 49 residues including signal peptide, significantly increases the catalytic efficiency of the enzyme.
    Journal of Molecular Catalysis B Enzymatic 06/2015; DOI:10.1016/j.molcatb.2015.06.001
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    ABSTRACT: Immobilised enzyme-catalysed conversions frequently provide specific advantages of selectivity over chemical conversions and further, facilitate continuous operation through biocatalyst retention and reuse. This study focuses on the development and modelling of an enzyme-catalysed continuous immobilised enzyme biocatalytic membrane reactor (BMR). The conversion of the amidase-catalysed lactamide to lactic acid process was used as an industrially representative system with which to evaluate the process performance of the BMR. The model was developed from unsteady state differential mass balances incorporating a second order enzyme decay. This model was validated from empirically determined conversions in dual experiments using 80 and 40 mM amide substrate, 6.4 and 20.1 mg immobilised amidase and a flow rate of 0.0005 and 0.0001 L/min respectively. Model predictions over a range of amidase amounts and stabilities, flow rates and initial amide concentrations quantified the direction and extent of the influence of these parameters on the maximum conversions attainable, consequently identifying the critical parameter ranges defining optimal BMR performance. Although the model has been developed and validated for the prediction of BMR performance of the specific lactamide-lactic acid system, it nevertheless has broad applicability for and relevance to broad-based prediction of the performance of immobilised enzyme BMR processes in general, irrespective of the specific enzyme or substrate moieties.
    Journal of Molecular Catalysis B Enzymatic 06/2015; 119:48-53. DOI:10.1016/j.molcatb.2015.05.015
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    ABSTRACT: A simple and efficient method of the synthesis of enantiomerically enriched, unknown acetoxymethyl aryl sulfoxides has been developed which is based on an enzyme-catalyzed hydrolysis of racemic substrates under the kinetic resolution conditions. The hydrolysis was performed not only in a buffer solution but also in diisopropyl ether in the absence of the external water added to give in some cases the products with ee up to 98%. The enantioselectivity of both procedures was dependent on the enzyme used and the aryl substituent, being lower for p-tolyl than for phenyl. A comparative asymmetric synthesis based on the oxidation of the corresponding sulfides using chiral oxidizing reagent turned out to be inferior to the method described. Absolute configuration of the newly synthesized compounds was ascribed on the basis of CD spectra.
    Journal of Molecular Catalysis B Enzymatic 05/2015; 118. DOI:10.1016/j.molcatb.2015.04.016
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    ABSTRACT: Cunninghamella blakesleeana AS 3.0970 and AS 3.0910 and C. elegans AS 3.2028 were first used for biotransforming three major prenylflavonoids from Psoralea corylifolia, namely bavachinin, bavachin, and isobavachalcone. A total of seven biotransformation products, including six new compounds, were obtained and identified. The agonistic activities of peroxisome proliferator-activated receptor-γ against substrates and biotransformation products were also evaluated.
    Journal of Molecular Catalysis B Enzymatic 05/2015; 118. DOI:10.1016/j.molcatb.2015.04.015
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    ABSTRACT: (R)-mandelate dehydrogenase (RMDH) has the potential to produce chiral mandelic acid. The present work reports isolation and identification of a Pseudomonas putida NUST506 contained RMDH. The strain was rod shaped with polar flagella, approximately 0.6-0.9 μm wide and 1.7-2.3 μm long. The RMDH was purified from the strain. The molecular weight of the enzyme was calculated to be 61 kDa. The optimal conditions for RMDH were pH 8.5 and 30 °C. At the optimum condition, the Km and kcat of the RMDH were 2.0 × 10−2 mM and 0.9 s−1 for (R)-mandelic acid, 1.8 × 10−2 mM and 0.9 s−1 for NAD+, as well as 1.5 × 10−2 mM and 0.3 s−1 for NADP+, respectively. The enzyme activity was increased by K+ and dithiothreitol (DTT), but obviously inhibited by Zn2+, Hg2+, sodium dodecyl sulfate (SDS) and ethylenediamine tetra-acetic acid (EDTA).
    Journal of Molecular Catalysis B Enzymatic 05/2015; DOI:10.1016/j.molcatb.2015.04.017
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    ABSTRACT: A carbonyl reductase from Gluconobacter oxydans (GoCR) exhibited good activity and strict enantioselectivity for the asymmetric reduction of a series of halogenated acetophenones, resulting in the corresponding S-alcohols. For efficient synthesis of alcohol products, an economical and satisfactory substrate-coupled cofactor regeneration system was constructed employing isopropanol as the co-substrate to regenerate NADH in situ. In the presence of 2.0 molar eq. of isopropanol, 500 mM o-chloroacetophenone was reduced to (S)-1-(2-chlorophenyl)-ethanol with >99% ee and a high conversion rate of 96% by recombinant E. coli BL21 cells overexpressing GoCR. In this reaction system, a slight excess of isopropanol as hydride source could drive the reduction reaction to near completion due to the speculated forming of an intramolecular hydrogen bond between the Cl group and the new obtained alcohol moiety of (S)-1-(2-chlorophenyl)-ethanol. Furthermore, other tested halogenated acetophenones at 100 or 200 mM substrate load were also reduced at 71%-96% conversion, affording S-configuration alcohols with >99% ee. Homology modeling and molecular dynamics simulation were performed to uncover the structural basis for the excellent enantioselectivity of GoCR toward halogenated acetophenones. These results imply the high potential of GoCR in the production of halogenated 1-phenylethanols, such as (S)-1-(2-chlorophenyl)-ethanol, an important chiral building block with wide application in pharmaceutical chemistry and fine chemicals.
    Journal of Molecular Catalysis B Enzymatic 05/2015; 118. DOI:10.1016/j.molcatb.2015.04.014