617-45-8Relevant articles and documents
Comparative study of ASNase immobilization on tannic acid-modified magnetic Fe3O4/SBA-15 nanoparticles to enhance stability and reusability
Noma, Samir Abbas Ali,Ulu, Ahmet,Acet, ?mür,Sanz, Raúl,Sanz-Pérez, Eloy S.,Odaba?i, Mehmet,Ate?, Burhan
, p. 4440 - 4451 (2020/03/27)
In this work, l-asparaginase was immobilized on tannic acid-modified magnetic mesoporous particles. In brief, Fe3O4/SBA-15/tannic acid magnetic particles were synthesized, and their structures and morphologies were fully characterized using various methods. The properties of the free and immobilized enzyme were examined in terms of pH, temperature, thermal stability, storage stability, and reusability. Moreover, the effects of metal ions, inhibitors and organic solvents on the activity of the immobilized enzyme were investigated. Compared to the free enzyme, the immobilized enzyme possessed better tolerance to changes in ambient temperature and pH. Additionally, thermal incubation results showed that the free enzyme lost its activity, while the immobilized enzyme exhibited the opposite behavior. Most strikingly, the immobilized l-asparaginase exhibited a high degree of activity (70%) after being reused 16 times while also demonstrating 71% and 63% storage stability of the initial activity even after 28 days at 4 °C and room temperature, respectively. Together with these results, l-asparaginase was successfully immobilized upon Fe3O4/SBA-15/tannic acid magnetic nanoparticles with improved stability properties. This support holds great potential and opens up a novel perspective for growing applications.
Electrosynthesis of amino acids from biomass-derivable acids on titanium dioxide
Fukushima, Takashi,Yamauchi, Miho
supporting information, p. 14721 - 14724 (2019/12/24)
Seven amino acids were electrochemically synthesized from biomass-derivable α-keto acids and NH2OH with faradaic efficiencies (FEs) of 77-99% using an earth-Abundant TiO2 catalyst. Furthermore, we newly constructed a flow-Type electrochemical reactor, named a "polymer electrolyte amino acid electrosynthesis cell", and achieved continuous production of alanine with an FE of 77%.
Catalytic amino acid production from biomass-derived intermediates
Deng, Weiping,Wang, Yunzhu,Zhang, Sui,Gupta, Krishna M.,Hülsey, Max J.,Asakura, Hiroyuki,Liu, Lingmei,Han, Yu,Karp, Eric M.,Beckham, Gregg T.,Dyson, Paul J.,Jiang, Jianwen,Tanaka, Tsunehiro,Wang, Ye,Yan, Ning
, p. 5093 - 5098 (2018/05/23)
Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived α-hydroxyl acids into α-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supported on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components.
Degradation of complexons derived from succinic acid under UV radiation
Smirnova,Khizhnyak,Nikol’skii,Khalyapina, Ya. M.,Pakhomov
, p. 507 - 511 (2017/08/02)
The destruction of complexons derived from succinic acid under the action of UV radiation was studied. IR spectroscopy, thin-layer paper chromatography, and complexometric titration were used to determine the destruction products of these complexons. It was found that the complexons decompose under UV irradiation substantially more easily than ethylenediaminetetraacetic acid does, and the products of their decomposition can undergo a biological utilization under natural conditions. The data obtained in the study make it possible to choose, instead of ethylenediaminetetraacetic acid, ligands that will be nearly fully destructible in the light without deteriorating the ecology.
Racemization of the aspartic acid residue of amyloid-β peptide by a radical reaction
Tambo, Koharu,Yamaguchi, Tomomi,Kobayashi, Keiko,Terauchi, Eri,Ichi, Ikuyo,Kojo, Shosuke
, p. 416 - 418 (2013/05/22)
Human amyloid-β peptide 1-42 (Aβ) was subjected to a radical reaction by using ascorbic acid and CuCl2. The percentage of D-aspartic acid (D-Asp) after 24 h had increased to 6.69 ± 0.09%, this being comparable with the reported D-Asp concentration of purified core amyloids in Alzheimer's disease patients. This racemization was significantly inhibited by radical scavengers. L-Alanine was also racemized during the same reaction.
Conductometric method for the rapid characterization of the substrate specificity of amine-transaminases
Schaetzle, Sebastian,Hoehne, Matthias,Robins, Karen,Bornscheuer, Uwe T.
body text, p. 2082 - 2086 (2010/08/20)
Amine-transaminases (ATAs, ω-transaminases, ω-TA) are PLP-dependent enzymes that catalyze amino group transfer reactions. In contrast to the widespread and wellknown amino acid-transaminases, ATAs are able to convert substrates lacking an a-carboxylic functional group. They have gained increased attention because of their potential for the asymmetric synthesis of optically active amines, which are frequently used as building blocks for the preparation of numerous pharmaceuticals. Having already introduced a fast kinetic assay based on the conversion of the model substrate α-methylbenzylamine for the characterization of the amino acceptor specificity, we now report on a kinetic conductivity assay for investigating the amino donor specificity of a given ATA. The course of an ATA-catalyzed reaction can be followed conductometrically since the conducting substrates, a positively charged amine and a negatively charged keto acid, are converted to nonconducting products, a noncharged ketone and a zwitterionic amino acid. The decrease of conductivity for the investigated reaction systems were determined to be 33-52 μS mM-1. In contrast to other ATA-assays previously described, with this approach all transamination reactions between any amine and any keto add can be monitored without the need for an additional enzyme or staining solutions. The assay was used for the characterization of a ATA from Rhodobacter sphaeroides, and the data obtained were in excellent agreement with gas chromatography analysis.
Mineral Amino Acid Polysaccharide Complex
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, (2010/02/17)
This document provides complexes comprising a mineral-amino acid compound and a polysaccharide. For example, the document provides compositions containing such complexes and methods of making and using such complexes.
Compositions, kits, and methods relating to the human FEZ1 gene, a novel tumor suppressor gene
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, (2008/06/13)
The invention relates to isolated polynucleotides homologous with a portion of one strand of the human tumor suppressor gene, FEZ1, and to the tumor suppressor protein encoded thereby, Fez1. The polynucleotides are useful, for example, as probes, primers, portions of expression vectors, and the like. The invention also includes diagnostic, therapeutic, cell proliferation enhancement, and screening methods which involve these polynucleotides and protein. The invention further includes kits useful for performing the methods of the invention.
Asparagine deaminase catalytic antibodies
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Page/Page column 3, (2010/02/11)
Transition state analogs are described which may be used to elicit antibodies that catalyze the conversion of asparagine to aspartic acid. Synthetic schemes are disclosed for making the transition state analogs which can than be attached to a carrier molecule to form an immunoconjugate. Immunoconjugates can be administered to an animal for the purpose of raising antibodies. Antibodies can in turn be used in pharmaceutical compositions which can be given to patients as part of a method of treating various conditions, particularly cancer.
HIGH-AFFINITY INTERLEUKIN-4 MUTEINS
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, (2008/06/13)
A recombinant human IL-4 mutein numbered in accordance with wild-type IL-4 wherein the mutein comprises at least one amino acid substitution in the binding surface of either the A- or C-alpha helices of the wild-type IL-4 whereby the mutein binds to the IL-4R alpha receptor with at least greater affinity than native IL-4. The substitution is more preferably selected from the group of positions consisting of, in the A-helix, positions 13 and 16, and in the C-helix, positions 81 and 89. A most preferred embodiment is the recombinant human IL-4 mutein wherein the substitution at position 13 is Thr to Asp. Pharmaceutical compositions, amino acid and polynucleotide sequences encoding the muteins, transformed host cells, antibodies to the muteins, and methods of treatment are also described.
