The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Ulf Hanefeld - One of the best experts on this subject based on the ideXlab platform.
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2-Deoxy-D-Ribose-5-phosphate aldolase (DERA): applications and modifications.
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:© 2018, The Author(s). 2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
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2 deoxy d ribose 5 phosphate aldolase dera applications and modifications
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
Akinari Yokoya - One of the best experts on this subject based on the ideXlab platform.
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Decomposition of 2-Deoxy-D-Ribose by irradiation with 0.6 keV electrons and by 0.5 keV ultrasoft X-rays.
International journal of radiation biology, 2004Co-Authors: Kentaro Fujii, Ken Akamatsu, Akinari YokoyaAbstract:Purpose: To compare the molecular decomposition of 2‐deoxy‐D‐ribose induced by 0.6 keV electron irradiation or by 0.5 keV ultrasoft X‐ray irradiation.Materials and methods: A thin film of 2‐deoxy‐D‐ribose was irradiated by two radiation sources: low‐energy (∼0.6 keV) electrons and ultrasoft X‐rays (∼0.5 keV). The positive ions that were desorbed from the sample during the irradiation were measured using a quadrupole mass spectrometer. The spectral changes in the X‐ray absorption near edge structure (XANES) were also examined after the irradiation.Results and discussion: The ions that were desorbed from 2‐deoxy‐D‐ribose due to electron irradiation were mainly H+, CHx+, C2Hx+, CO+, CHxO+, C3Hx+, C2HxO+ and C3HxO+ (x=1, 2, and 3) ions. These ions were the same as those observed in desorption due to ultrasoft X‐ray irradiation. The XANES spectral changes induced by electron irradiation showed C‐O bond cleavage in the molecule and C=O bond formation in the surface residues. These results show that intensive mo...
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Infrared spectral change in 2-deoxy- D-ribose by irradiation with monochromatic photons around oxygen K-edge
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2003Co-Authors: Ken Akamatsu, Kentaro Fujii, Akinari YokoyaAbstract:Abstract Analyses of chemical changes in DNA by energy deposition from ionizing radiation are quite important to strictly know characteristics of radiobiological effects. Monochromatic photons from synchrotron radiation are one of the powerful probes to investigate the effects. As a step for the aim, chemical analyses by Fourier-transform infrared spectroscopy of the samples irradiated with the monochromatic photons were performed. It appeared that 2-deoxy- d -ribose irradiated around the energy of oxygen K-edge contained CO or CC, which would be responsible for a direct strand break of DNA. These data are noteworthy to find not only the strand scission at 2-deoxy- d -ribose moiety by the direct energy deposition by photon but also the following radiobiological responses such as cell killing or mutation.
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X‐ray absorption near‐edge structure (XANES) spectral changes of 2‐deoxy‐D‐ribose by irradiation within the energy region around the oxygen K‐shell absorption edge
Journal of Synchrotron Radiation, 2001Co-Authors: Ken Akamatsu, Akinari YokoyaAbstract:The physicochemical characteristics of 2-Deoxy-D-Ribose moieties in DNA strands are important to understand biological radiation stress. So, the X-ray absorption near edge structure (XANES) of 2-Deoxy-D-Ribose within the energy region around the oxygen K-shell absorption edge was measured. 2-Deoxy-D-Ribose was exposed to 3 energies of X-rays, i.e. 526.3 eV (below O 1s*), 537.8 eV (at the absorption peak of O 1s*) and 552.6 eV (above O 1s*) for given periods. Slight differences in spectral changes were seen in the each irradiation energy, suggesting in fact that the chemical state and following rearranged chemical structure of 2-Deoxy-D-Ribose may be different between the three irradiation energies.
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X-ray absorption near-edge structure (XANES) spectral changes of 2-Deoxy-D-Ribose by irradiation within the energy region around the oxygen K-shell absorption edge.
Journal of synchrotron radiation, 2001Co-Authors: Ken Akamatsu, Akinari YokoyaAbstract:The physicochemical characteristics of 2-Deoxy-D-Ribose moieties in DNA strands are important to understand biological radiation stress. So, the X-ray absorption near edge structure (XANES) of 2-Deoxy-D-Ribose within the energy region around the oxygen K-shell absorption edge was measured. 2-Deoxy-D-Ribose was exposed to 3 energies of X-rays, i.e., 526.3 eV (below O 1s-->pi*), 537.8 eV (at the absorption peak of O 1s-->sigma*) and 552.6 eV (above O 1s-->sigma*) for given periods. Slight differences in spectral changes were seen in the each irradiation energy, suggesting in fact that the chemical state and following rearranged chemical structure of 2-Deoxy-D-Ribose may be different between the 3 irradiation energies.
Eman M. M. Abdelraheem - One of the best experts on this subject based on the ideXlab platform.
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2-Deoxy-D-Ribose-5-phosphate aldolase (DERA): applications and modifications.
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:© 2018, The Author(s). 2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
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2 deoxy d ribose 5 phosphate aldolase dera applications and modifications
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
Meera Haridas - One of the best experts on this subject based on the ideXlab platform.
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2-Deoxy-D-Ribose-5-phosphate aldolase (DERA): applications and modifications.
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:© 2018, The Author(s). 2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
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2 deoxy d ribose 5 phosphate aldolase dera applications and modifications
Applied Microbiology and Biotechnology, 2018Co-Authors: Meera Haridas, Eman M. M. Abdelraheem, Ulf HanefeldAbstract:2-Deoxy-D-Ribose-5-phosphate aldolase (DERA) is a class I aldolase that offers access to several building blocks for organic synthesis. It catalyzes the stereoselective C–C bond formation between acetaldehyde and numerous other aldehydes. However, the practical application of DERA as a biocatalyst is limited by its poor tolerance towards industrially relevant concentrations of aldehydes, in particular acetaldehyde. Therefore, the development of proper experimental conditions, including protein engineering and/or immobilization on appropriate supports, is required. The present review is aimed to provide a brief overview of DERA, its history, and progress made in understanding the functioning of the enzyme. Furthermore, the current understanding regarding aldehyde resistance of DERA and the various optimizations carried out to modify this property are discussed.
Takeshi Sekine - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of [5'-13C]ribonucleosides and 2'-deoxy[5'-13C]ribonucleosides.
Journal of Organic Chemistry, 2002Co-Authors: Etsuko Kawashima, Kaoru Umabe, Takeshi SekineAbstract:The present efficient synthesis of [5‘-13C]ribonucleosides and 2‘-deoxy[5‘-13C]ribonucleosides is characterized by the synthesis of the d-[5-13C]ribose derivative as an intermediate via the Wittig reaction of 4-aldehydo-d-erythrose dialkyl acetals with Ph3P13CH3I−BuLi to introduce the 13C label at the 5-position of a pentose. This was followed by the highly diastereoselective osmium dihydroxylation for the preparation of 2,3-di-O-benzyl-d-[5-13C]ribose dialkyl acetal and the cyclization from d-[5-13C]ribose dialkyl acetal derivatives to the alkyl d-[5-13C]ribofuranoside derivative by the use of LiBF4. The obtained d-[5-13C]ribose derivative was converted into [5‘-13C]ribonucleosides and subsequently into the corresponding 2‘-deoxynucleosides.
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Synthesis of 2′-Deoxy[5′-13C]Ribonucleotides and HMQC-Noesy NMR Study of the Dickerson's Dodecamer with 13C-Labeling at the 5′ Positions
Nucleosides and Nucleotides, 1999Co-Authors: Etsuko Kawashima, Kaoru Umabe, Takeshi Sekine, Yuh-ki Naito, Kazuo Kamaike, Chojiro Kojima, Toshimi Mizukoshi, Ei-ichiro Suzuki, Yoshiharu IshidoAbstract:Abstract In addition to the synthesis of 2′-deoxy[5′-13C]ribonucleosides (6) via the D-[5-13C]ribose derivative (4), the construction of the corresponding dodecanucleotide with the Dickerson's sequence and its HMQC-NOESY NMR analysis are described.
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Synthesis of [5'-11C]ribonucleoside and -2'-deoyribonucleoside derivatives from D-ribose.
Nucleic acids symposium series, 1995Co-Authors: Takeshi Sekine, Kawashima E, Yoshiharu IshidoAbstract:An approach to the synthesis of 2'-deoxy[5'-13C]ribonucleosides was achieved by the coupling reaction of a nucleic acid base derivative with D-[5-13C]ribose derivative (8). Compound 8 was derived from D-ribose (1) by way of methyl 2,3-di-O-benzyl(Bn)-D-ribofuranoside (2), 2,3-di-O-Bn-D-ribose diethyl dithioacetal (3), 2,3-di-O-Bn-D-ribose dibenzyl acetal (4), and 4-aldehydo-2,3-di-O-Bn-D-erythrose dibenzyl acetal (5), which was then successively subjected to Wittig reaction using Ph3P13CH3I-BuLi, highly stereoselective hydroxylation with OsO4 to give 2,3-di-O-Bn-D-ribose dibenzyl acetal (7), debenzylation with H2-Pd/C. The resulting 8 was subjected to coupling reaction with a nucleic acid base to give [5'-13C]ribonucleosides. The products were derived into the corresponding 2'-deoxy[5'-13C]ribonucleoside derivatives by the established manner.
