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Special Issue "Enzyme-Catalyzed Reactions"

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A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Organic Synthesis".

Deadline for manuscript submissions: closed (10 November 2014)

Special Issue Editor

Guest Editor
Prof. Dr. Lajos Novak (Website)

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1111 Budapest, Szt. Geller ter 4, Hungary
Fax: +36 1 4633297
Interests: synthetic organic chemistry; rearrangement reactions; enzyme-catalyzed reaction, insect pheromone; insect growth regulators; lipoxygenase enzyme inhibitors; tryptamine derivatives

Special Issue Information

Dear Colleagues,

To generate chirality is essential in synthetic organic chemistry, medicinal chemistry and drug discovery. Besides conventional chemical synthetic methods, enzymes offer an excellent tool for asymmetric synthesis and enantioselective resolution. Enzyme-catalyzed reactions show excellent chemo-, region-, and stereocontrol. Furthermore, these reactions generally proceed at room temperature at pH≈ 7, in water and don’t require protecting-group manipulations. Considering the advantage of the enzyme catalyzed reactions, this technique may be widely used in chemical and biological research.

This Special Issue on enzyme-catalyzed reactions will offer a good possibility to illustrate the asymmetric catalysis with enzyme, its application in organic synthesis, and the mechanistic principles that govern these reactions. I strongly encourage authors to submit manuscripts for this Special Issue.

Dr. Lajos Novak
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs).


Keywords

  • enzymes
  • oxidoreductases
  • transferases
  • hydrolases
  • lyases
  • osomerases
  • ligases
  • immobilized enzyme
  • enzyme engineering
  • cofactors and coenzymes
  • industrial applications

Published Papers (18 papers)

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Research

Jump to: Review

Open AccessArticle Characterization of a (2R,3R)-2,3-Butanediol Dehydrogenase from Rhodococcus erythropolis WZ010
Molecules 2015, 20(4), 7156-7173; doi:10.3390/molecules20047156
Received: 12 March 2015 / Revised: 13 April 2015 / Accepted: 14 April 2015 / Published: 20 April 2015
Cited by 3 | PDF Full-text (1915 KB) | HTML Full-text | XML Full-text
Abstract
The gene encoding a (2R,3R)-2,3-butanediol dehydrogenase from Rhodococcus erythropolis WZ010 (ReBDH) was over-expressed in Escherichia coli and the resulting recombinant ReBDH was successfully purified by Ni-affinity chromatography. The purified ReBDH in the native form was found to exist [...] Read more.
The gene encoding a (2R,3R)-2,3-butanediol dehydrogenase from Rhodococcus erythropolis WZ010 (ReBDH) was over-expressed in Escherichia coli and the resulting recombinant ReBDH was successfully purified by Ni-affinity chromatography. The purified ReBDH in the native form was found to exist as a monomer with a calculated subunit size of 37180, belonging to the family of the zinc-containing alcohol dehydrogenases. The enzyme was NAD(H)-specific and its optimal activity for acetoin reduction was observed at pH 6.5 and 55 °C. The optimal pH and temperature for 2,3-butanediol oxidation were pH 10 and 45 °C, respectively. The enzyme activity was inhibited by ethylenediaminetetraacetic acid (EDTA) or metal ions Al3+, Zn2+, Fe2+, Cu2+ and Ag+, while the addition of 10% (v/v) dimethyl sulfoxide (DMSO) in the reaction mixture increased the activity by 161.2%. Kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for diacetyl and NADH in comparison to those for (2R,3R)-2,3-butanediol and NAD+. The activity of acetoin reduction was 7.7 times higher than that of (2R,3R)-2,3-butanediol oxidation when ReBDH was assayed at pH 7.0, suggesting that ReBDH-catalyzed reaction in vivo might favor (2R,3R)-2,3-butanediol formation rather than (2R,3R)-2,3-butanediol oxidation. The enzyme displayed absolute stereospecificity in the reduction of diacetyl to (2R,3R)-2,3-butanediol via (R)-acetoin, demonstrating its potential application on the synthesis of (R)-chiral alcohols. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Facile Synthesis of Bis(indolyl)methanes Catalyzed by α-Chymotrypsin
Molecules 2014, 19(12), 19665-19677; doi:10.3390/molecules191219665
Received: 15 October 2014 / Revised: 20 November 2014 / Accepted: 21 November 2014 / Published: 27 November 2014
Cited by 4 | PDF Full-text (298 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A mild and efficient method catalyzed by α-chymotrypsin was developed for the synthesis of bis(indolyl)methanes through a cascade process between indole and aromatic aldehydes. In the ethanol aqueous solution, a green medium, a wide range of aromatic aldehydes could react with indole [...] Read more.
A mild and efficient method catalyzed by α-chymotrypsin was developed for the synthesis of bis(indolyl)methanes through a cascade process between indole and aromatic aldehydes. In the ethanol aqueous solution, a green medium, a wide range of aromatic aldehydes could react with indole to afford the desired products with moderate to good yields (from 68% to 95%) using a little α-chymotrypsin as catalyst. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessCommunication Towards Recyclable NAD(P)H Regeneration Catalysts
Molecules 2012, 17(8), 9835-9841; doi:10.3390/molecules17089835
Received: 14 June 2012 / Revised: 1 August 2012 / Accepted: 8 August 2012 / Published: 15 August 2012
Cited by 14 | PDF Full-text (213 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Rh(III)-TsDPEN, an immobilized analog of the well-known [Cp*Rh(bpy)(H2O)]2+ was evaluated as a heterogeneous, recyclable regeneration catalyst for reduced oxidoreductase cofactors [NAD(P)H]. Repeated use of this catalyst was established and the catalytic properties were initially investigated. Apparently, Rh(III)-TsDPEN [...] Read more.
Rh(III)-TsDPEN, an immobilized analog of the well-known [Cp*Rh(bpy)(H2O)]2+ was evaluated as a heterogeneous, recyclable regeneration catalyst for reduced oxidoreductase cofactors [NAD(P)H]. Repeated use of this catalyst was established and the catalytic properties were initially investigated. Apparently, Rh(III)-TsDPEN is prone to severe diffusion limitations, necessitating further developments. Overall, a promising concept for chemoenzymatic redox catalysis is proposed, which may overcome some of the current limitations such as catalyst cost and incompatibility of Rh with some biocatalysts. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Low Operational Stability of Enzymes in Dry Organic Solvents: Changes in the Active Site Might Affect Catalysis
Molecules 2012, 17(2), 1870-1882; doi:10.3390/molecules17021870
Received: 27 October 2011 / Revised: 7 February 2012 / Accepted: 7 February 2012 / Published: 14 February 2012
Cited by 3 | PDF Full-text (322 KB)
Abstract
The potential of enzyme catalysis in organic solvents for synthetic applications has been overshadowed by the fact that their catalytic properties are affected by organic solvents. In addition, it has recently been shown that an enzyme’s initial activity diminishes considerably after prolonged [...] Read more.
The potential of enzyme catalysis in organic solvents for synthetic applications has been overshadowed by the fact that their catalytic properties are affected by organic solvents. In addition, it has recently been shown that an enzyme’s initial activity diminishes considerably after prolonged exposure to organic media. Studies geared towards understanding this last drawback have yielded unclear results. In the present work we decided to use electron paramagnetic resonance spectroscopy (EPR) to study the motion of an active site spin label (a nitroxide free radical) during 96 h of exposure of the serine protease subtilisin Carlsberg to four different organic solvents. Our EPR data shows a typical two component spectra that was quantified by the ratio of the anisotropic and isotropic signals. The isotropic component, associated with a mobile nitroxide free radical, increases during prolonged exposure to all solvents used in the study. The maximum increase (of 43%) was observed in 1,4-dioxane. Based on these and previous studies we suggest that prolonged exposure of the enzyme to these solvents provokes a cascade of events that could induce substrates to adopt different binding conformations. This is the first EPR study of the motion of an active-site spin label during prolonged exposure of an enzyme to organic solvents ever reported. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle A QM/MM–Based Computational Investigation on the Catalytic Mechanism of Saccharopine Reductase
Molecules 2011, 16(10), 8569-8589; doi:10.3390/molecules16108569
Received: 5 September 2011 / Revised: 27 September 2011 / Accepted: 30 September 2011 / Published: 12 October 2011
Cited by 6 | PDF Full-text (1423 KB) | Supplementary Files
Abstract
Saccharopine reductase from Magnaporthe grisea, an NADPH-containing enzyme in the α-aminoadipate pathway, catalyses the formation of saccharopine, a precursor to L-lysine, from the substrates glutamate and α-aminoadipate-δ-semialdehyde. Its catalytic mechanism has been investigated using quantum mechanics/molecular mechanics (QM/MM) ONIOM-based approaches. In [...] Read more.
Saccharopine reductase from Magnaporthe grisea, an NADPH-containing enzyme in the α-aminoadipate pathway, catalyses the formation of saccharopine, a precursor to L-lysine, from the substrates glutamate and α-aminoadipate-δ-semialdehyde. Its catalytic mechanism has been investigated using quantum mechanics/molecular mechanics (QM/MM) ONIOM-based approaches. In particular, the overall catalytic pathway has been elucidated and the effects of electron correlation and the anisotropic polar protein environment have been examined via the use of the ONIOM(HF/6-31G(d):AMBER94) and ONIOM(MP2/6-31G(d)//HF/6-31G(d):AMBER94) methods within the mechanical embedding formulism and ONIOM(MP2/6-31G(d)//HF/6-31G(d):AMBER94) and ONIOM(MP2/6-311G(d,p)//HF/6-31G(d):AMBER94) within the electronic embedding formulism. The results of the present study suggest that saccharopine reductase utilises a substrate-assisted catalytic pathway in which acid/base groups within the cosubstrates themselves facilitate the mechanistically required proton transfers. Thus, the enzyme appears to act most likely by binding the three required reactant molecules glutamate, α-aminoadipate-δ-semialdehyde and NADPH in a manner and polar environment conducive to reaction. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle Enzymatic Kinetic Resolution of tert-Butyl 2-(1-Hydroxyethyl)phenylcarbamate, A Key Intermediate to Chiral Organoselenanes and Organotelluranes
Molecules 2011, 16(9), 8098-8109; doi:10.3390/molecules16098098
Received: 19 August 2011 / Revised: 14 September 2011 / Accepted: 15 September 2011 / Published: 20 September 2011
Cited by 1 | PDF Full-text (552 KB)
Abstract
The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl) phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B), leading to the optically pure (R)- and (S)-enantiomers. [...] Read more.
The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl) phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B), leading to the optically pure (R)- and (S)-enantiomers. The enzymatic process showed excellent enantioselectivity (E > 200). (R)- and (S)-tert-butyl 2-(1-hydroxyethyl)phenylcarbamate were easily transformed into the corresponding (R)- and (S)-1-(2-aminophenyl)ethanols. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle Optimized Enzymatic Synthesis of Hesperidin Fatty Acid Esters in a Two-Phase System Containing Ionic Liquid
Molecules 2011, 16(8), 7171-7182; doi:10.3390/molecules16087171
Received: 29 June 2011 / Revised: 16 August 2011 / Accepted: 17 August 2011 / Published: 23 August 2011
Cited by 7 | PDF Full-text (545 KB)
Abstract
Response surface methodology (RSM) based on a five-level, three-variable central composite design (CCD) was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB) in a two-phase system [...] Read more.
Response surface methodology (RSM) based on a five-level, three-variable central composite design (CCD) was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB) in a two-phase system containing [bmim]BF4. The three variables studied (molar ratio of hesperidin to decanoic acid, [bmim]BF4/acetone ratio and lipase concentration) significantly affected the conversion yield of acylated hesperidin derivative. Verification experiments confirmed the validity of the predicted model. The lipase showed higher conversion degree in a two-phase system using [bmim]BF4 and acetone compared to that in pure acetone. Under the optimal reaction conditions carried out in a single-step biocatalytic process when the water content was kept lower than 200 ppm, the maximum acylation yield was 53.6%. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Chemo-Enzymatic Synthesis of a Multi-Useful Chiral Building Block Molecule for the Synthesis of Medicinal Compounds
Molecules 2011, 16(8), 6747-6757; doi:10.3390/molecules16086747
Received: 4 July 2011 / Revised: 2 August 2011 / Accepted: 4 August 2011 / Published: 9 August 2011
Cited by 5 | PDF Full-text (255 KB)
Abstract Optical resolution of 2-methyl-2-nitrobut-3-en-1-ol has been accomplished using a “low-temperature lipase-catalyzed transesterification” carried out at −40 °C. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Chemo-Enzymatic Synthesis of Ester-Linked Docetaxel-Monosaccharide Conjugates as Water-Soluble Prodrugs
Molecules 2011, 16(8), 6769-6777; doi:10.3390/molecules16086769
Received: 24 June 2011 / Revised: 28 July 2011 / Accepted: 3 August 2011 / Published: 9 August 2011
Cited by 4 | PDF Full-text (115 KB)
Abstract
Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. [...] Read more.
Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside were effectively hydrolyzed by the relevant enzyme(s) of human cancer cells to release docetaxel, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside was relatively resistant under similar conditions. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside showed in vitro cytotoxic activity against human cancer cells, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside exerted low cytotoxicity. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Enzymatic Synthesis of Fatty Hydroxamic Acid Derivatives Based on Palm Kernel Oil
Molecules 2011, 16(8), 6634-6644; doi:10.3390/molecules16086634
Received: 20 June 2011 / Revised: 19 July 2011 / Accepted: 19 July 2011 / Published: 5 August 2011
Cited by 7 | PDF Full-text (438 KB)
Abstract
Fatty hydroxamic acid derivatives were synthesized using Lipozyme TL IM catalyst at biphasic medium as the palm kernel oil was dissolved in hexane and hydroxylamine derivatives were dissolved in water: (1) N-methyl fatty hydroxamic acids (MFHAs); (2) N-isopropyl fatty hydroxamic [...] Read more.
Fatty hydroxamic acid derivatives were synthesized using Lipozyme TL IM catalyst at biphasic medium as the palm kernel oil was dissolved in hexane and hydroxylamine derivatives were dissolved in water: (1) N-methyl fatty hydroxamic acids (MFHAs); (2) N-isopropyl fatty hydroxamic acids (IPFHAs) and (3) N-benzyl fatty hydroxamic acids (BFHAs) were synthesized by reaction of palm kernel oil and N-methyl hydroxylamine (N-MHA), N-isopropyl hydroxylamine (N-IPHA) and N-benzyl hydroxylamine (N-BHA), respectively. Finally, after separation the products were characterized by color testing, elemental analysis, FT-IR and 1H-NMR spectroscopy. For achieving the highest conversion percentage of product the optimum molar ratio of reactants was obtained by changing the ratio of reactants while other reaction parameters were kept constant. For synthesis of MFHAs the optimum mol ratio of N-MHA/palm kernel oil = 6/1 and the highest conversion was 77.8%, for synthesis of IPFHAs the optimum mol ratio of N-IPHA/palm kernel oil = 7/1 and the highest conversion was 65.4% and for synthesis of BFHAs the optimum mol ratio of N-BHA/palm kernel oil = 7/1 and the highest conversion was 61.7%. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Substrate Promiscuity of N-Acetylhexosamine 1-Kinases
Molecules 2011, 16(8), 6396-6407; doi:10.3390/molecules16086396
Received: 1 July 2011 / Revised: 22 July 2011 / Accepted: 25 July 2011 / Published: 28 July 2011
Cited by 23 | PDF Full-text (628 KB)
Abstract
N-Acetylhexosamine 1-kinase (NahK) catalyzes the direct addition of a phosphate from adenosine 5'-triphosphate (ATP) to the anomeric position of N-acetylhexosamine and shows similar activity towards N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc). Herein we report the cloning, characterization, and substrate [...] Read more.
N-Acetylhexosamine 1-kinase (NahK) catalyzes the direct addition of a phosphate from adenosine 5'-triphosphate (ATP) to the anomeric position of N-acetylhexosamine and shows similar activity towards N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc). Herein we report the cloning, characterization, and substrate specificity studies of two NahKs from Bifidobacterium infantis ATCC15697 and Bifidobacterium longum ATCC55813, respectively. A new capillary electrophoresis assay method has been developed for enzyme activity assays. Both enzymes have a good expression level in E. coli (180–185 mg/L culture) and can tolerate diverse modifications at C2 of GlcNAc and GalNAc. Various GlcNAc derivatives with C6, both C2 and C6, as well as both C2 and C3 modifications are tolerable substrates for the newly cloned NahKs. Quite interestingly, despite of their low activities toward glucose and galactose, the activities of both NahKs are much higher for mannose and some of its C2, C4, and C6 derivatives. These NahKs are excellent catalysts for enzymatic and chemoenzymatic synthesis of carbohydrates. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle Integrated One-Pot Enrichment and Immobilization of Styrene Monooxygenase (StyA) Using SEPABEAD EC-EA and EC-Q1A Anion-Exchange Carriers
Molecules 2011, 16(7), 5975-5988; doi:10.3390/molecules16075975
Received: 23 June 2011 / Accepted: 12 July 2011 / Published: 18 July 2011
Cited by 4 | PDF Full-text (549 KB)
Abstract
A straightforward one-pot procedure combining enrichment and immobilization of recombinantely expressed FADH2 dependent styrene monooxygenase (StyA) directly from Escherichia coli cell extracts was investigated. Sepabeads EC-EA and EC-Q1A anion-exchange carriers were employed to non-covalently adsorb StyA from the cell extracts depending [...] Read more.
A straightforward one-pot procedure combining enrichment and immobilization of recombinantely expressed FADH2 dependent styrene monooxygenase (StyA) directly from Escherichia coli cell extracts was investigated. Sepabeads EC-EA and EC-Q1A anion-exchange carriers were employed to non-covalently adsorb StyA from the cell extracts depending on basic parameters such as varying initial protein concentrations and pH. The protein fraction of the cell extract contained around 25% StyA. At low initial protein concentrations (2.5 mg mL−1) and pH 6, the enzyme could be enriched up to 52.4% on Sepabeads EC-EA and up to 46.0% on Sepabeads EC-Q1A, accounting for an almost complete StyA adsorption from the cell extracts. Higher initial protein concentrations were necessary to exploit the high loading capacity of the beads. At 20 mg mL−1, up to 37.6% of the theoretical bead loading capacity could be utilized for StyA binding using Sepabeads EC-EA, and 34.0% using Sepabeads EC-Q1A. For both carriers, protein leakage under reaction conditions could be reduced to less than 2%. During assays, the FADH2 cofactor necessary for StyA activity was supplied by the NADH-FAD reductase component styrene monooxygenase B (StyB). StyA immobilized on Sepabeads EC-Q1A displayed twice as high styrene epoxidation rates (0.2 U mgStyA−1) as compared to Sepabeads EC-EA. This activity could be increased to 0.7 U mgStyA−1 by co-immobilizing StyB on Sepabeads EC-Q1A, which corresponds to 33% of the soluble StyA activity. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle Biocatalytic Resolution of Enantiomeric Mixtures of 1-Aminoethanephosphonic Acid
Molecules 2011, 16(7), 5896-5904; doi:10.3390/molecules16075896
Received: 29 June 2011 / Revised: 12 July 2011 / Accepted: 12 July 2011 / Published: 14 July 2011
Cited by 7 | PDF Full-text (238 KB)
Abstract
Several fungal strains, namely Bauveria bassiana, Cuninghamella echinulata, Aspergillus fumigatus, Penicillium crustosum and Cladosporium herbarum, were used as biocatalysts to resolve racemic mixtures of 1-aminoethanephosphonic acid using L/D amino acid oxidase activity. The course of reaction was analyzed by 31P-NMR [...] Read more.
Several fungal strains, namely Bauveria bassiana, Cuninghamella echinulata, Aspergillus fumigatus, Penicillium crustosum and Cladosporium herbarum, were used as biocatalysts to resolve racemic mixtures of 1-aminoethanephosphonic acid using L/D amino acid oxidase activity. The course of reaction was analyzed by 31P-NMR in the presence of cyclodextrin used as chiral discriminating agent. The best result (42% e.e of R-isomer) was obtained with a strain of Cuninghamella echinulata. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessArticle On the Reducible Character of Haldane-Radić Enzyme Kinetics to Conventional and Logistic Michaelis-Menten Models
Molecules 2011, 16(4), 3128-3145; doi:10.3390/molecules16043128
Received: 11 March 2011 / Revised: 13 April 2011 / Accepted: 13 April 2011 / Published: 13 April 2011
Cited by 7 | PDF Full-text (423 KB)
Abstract
The conceptual and practical issues regarding the reduction of the Haldane-Radić enzymic mechanism, specific for cholinesterase kinetics, to the consecrated or logistically modified Michaelis-Menten kinetics, specific for some mutant enzymes, are here clarified as due to the limited initial substrate concentration, through [...] Read more.
The conceptual and practical issues regarding the reduction of the Haldane-Radić enzymic mechanism, specific for cholinesterase kinetics, to the consecrated or logistically modified Michaelis-Menten kinetics, specific for some mutant enzymes, are here clarified as due to the limited initial substrate concentration, through detailed initial rate and progress curve analysis, even when other classical conditions for such equivalence are not entirely fulfilled. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle White Spot Syndrome Virus Orf514 Encodes a Bona Fide DNA Polymerase
Molecules 2011, 16(1), 532-542; doi:10.3390/molecules16010532
Received: 16 November 2010 / Revised: 19 December 2010 / Accepted: 11 January 2011 / Published: 12 January 2011
Cited by 5 | PDF Full-text (445 KB)
Abstract
White spot syndrome virus (WSSV) is the causative agent of white spot syndrome, one of the most devastating diseases in shrimp aquaculture. The genome of WSSV includes a gene that encodes a putative family B DNA polymerase (ORF514), which is 16% identical [...] Read more.
White spot syndrome virus (WSSV) is the causative agent of white spot syndrome, one of the most devastating diseases in shrimp aquaculture. The genome of WSSV includes a gene that encodes a putative family B DNA polymerase (ORF514), which is 16% identical in amino acid sequence to the Herpes virus 1 DNA polymerase. The aim of this work was to demonstrate the activity of the WSSV ORF514-encoded protein as a DNA polymerase and hence a putative antiviral target. A 3.5 kbp fragment encoding the conserved polymerase and exonuclease domains of ORF514 was overexpressed in bacteria. The recombinant protein showed polymerase activity but with very low level of processivity. Molecular modeling of the catalytic protein core encoded in ORF514 revealed a canonical polymerase fold. Amino acid sequence alignments of ORF514 indicate the presence of a putative PIP box, suggesting that the encoded putative DNA polymerase may use a host processivity factor for optimal activity. We postulate that WSSV ORF514 encodes a bona fide DNA polymerase that requires accessory proteins for activity and maybe target for drugs or compounds that inhibit viral DNA replication. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)

Review

Jump to: Research

Open AccessReview Green Polymer Chemistry: Enzyme Catalysis for Polymer Functionalization
Molecules 2015, 20(5), 9358-9379; doi:10.3390/molecules20059358
Received: 11 April 2015 / Accepted: 15 May 2015 / Published: 21 May 2015
Cited by 4 | PDF Full-text (2577 KB) | HTML Full-text | XML Full-text
Abstract
Enzyme catalyzed reactions are green alternative approaches to functionalize polymers compared to conventional methods. This technique is especially advantageous due to the high selectivity, high efficiency, milder reaction conditions, and recyclability of enzymes. Selected reactions can be conducted under solventless conditions without [...] Read more.
Enzyme catalyzed reactions are green alternative approaches to functionalize polymers compared to conventional methods. This technique is especially advantageous due to the high selectivity, high efficiency, milder reaction conditions, and recyclability of enzymes. Selected reactions can be conducted under solventless conditions without the application of metal catalysts. Hence this process is becoming more recognized in the arena of biomedical applications, as the toxicity created by solvents and metal catalyst residues can be completely avoided. In this review we will discuss fundamental aspects of chemical reactions biocatalyzed by Candida antarctica lipase B, and their application to create new functionalized polymers, including the regio- and chemoselectivity of the reactions. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
Open AccessReview Linking Protein Motion to Enzyme Catalysis
Molecules 2015, 20(1), 1192-1209; doi:10.3390/molecules20011192
Received: 29 November 2014 / Accepted: 7 January 2015 / Published: 13 January 2015
Cited by 6 | PDF Full-text (3227 KB) | HTML Full-text | XML Full-text
Abstract
Enzyme motions on a broad range of time scales can play an important role in various intra- and intermolecular events, including substrate binding, catalysis of the chemical conversion, and product release. The relationship between protein motions and catalytic activity is of contemporary [...] Read more.
Enzyme motions on a broad range of time scales can play an important role in various intra- and intermolecular events, including substrate binding, catalysis of the chemical conversion, and product release. The relationship between protein motions and catalytic activity is of contemporary interest in enzymology. To understand the factors influencing the rates of enzyme-catalyzed reactions, the dynamics of the protein-solvent-ligand complex must be considered. The current review presents two case studies of enzymes—dihydrofolate reductase (DHFR) and thymidylate synthase (TSase)—and discusses the role of protein motions in their catalyzed reactions. Specifically, we will discuss the utility of kinetic isotope effects (KIEs) and their temperature dependence as tools in probing such phenomena. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessReview Enzyme-Immobilized Microfluidic Process Reactors
Molecules 2011, 16(7), 6041-6059; doi:10.3390/molecules16076041
Received: 24 June 2011 / Revised: 13 July 2011 / Accepted: 17 July 2011 / Published: 19 July 2011
Cited by 66 | PDF Full-text (1722 KB)
Abstract
Microreaction technology, which is an interdisciplinary science and engineering area, has been the focus of different fields of research in the past few years. Several microreactors have been developed. Enzymes are a type of catalyst, which are useful in the production of [...] Read more.
Microreaction technology, which is an interdisciplinary science and engineering area, has been the focus of different fields of research in the past few years. Several microreactors have been developed. Enzymes are a type of catalyst, which are useful in the production of substance in an environmentally friendly way, and they also have high potential for analytical applications. However, not many enzymatic processes have been commercialized, because of problems in stability of the enzymes, cost, and efficiency of the reactions. Thus, there have been demands for innovation in process engineering, particularly for enzymatic reactions, and microreaction devices represent important tools for the development of enzyme processes. In this review, we summarize the recent advances of microchannel reaction technologies especially for enzyme immobilized microreactors. We discuss the manufacturing process of microreaction devices and the advantages of microreactors compared to conventional reaction devices. Fundamental techniques for enzyme immobilized microreactors and important applications of this multidisciplinary technology are also included in our topics. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Type of the Paper: Review
Title: Linking Protein Motions to Enzyme Catalysis
Authors: Priyanka Narendra Singh, Don Thelma Abeysinghe, and Amnon Kohen
Affiliations: Department of Chemistry, The University of Iowa, Iowa City, IA 52242, USA
Abstract: Enzyme motions on a broad range of time scales can play an important role in various intermolecular events including substrate binding and product release in achieving the catalyzed chemical conversion. Therefore, the relationship between protein motions and the catalytic activity is of contemporary interest in enzymology. To understand the factors influencing the rates of enzyme catalyzed reactions, it has become apparent that dynamics of protein as well as its environment must be considered. The current review presents two case studies of enzymes: dihydrofolate reductase (DHFR) and thymidylate synthase (TSase), and discuss the role of protein motions in catalyzed reaction. We will discuss the use of kinetic isotope effect as an effective tool in probing such a role in the enzyme-catalyzed reactions.

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