- Rational engineering ofAcinetobacter tandoiiglutamate dehydrogenase for asymmetric synthesis ofl-homoalanine through biocatalytic cascades
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l-Homoalanine, a useful building block for the synthesis of several chiral drugs, is generally synthesized through biocascades using natural amino acids as cheap starting reactants. However, the addition of expensive external cofactors and the low efficiency of leucine dehydrogenases towards the intermediate 2-ketobutyric acid are two major challenges in industrial applications. Herein, a dual cofactor-dependent glutamate dehydrogenase fromAcinetobacter tandoii(AtGluDH) was identified to help make full use of the intracellular pool of cofactors when using whole-cell catalysis. Through reconstruction of the hydrophobic network between the enzyme and the terminal methyl group of the substrate 2-ketobutyric acid, the strict substrate specificity ofAtGluDH towards α-ketoglutarate was successfully changed, and the activity obtained by the most effective mutant (K76L/T180C) was 17.2 times higher than that of the wild-type protein. A three-enzyme co-expression system was successfully constructed in order to help release the mass transfer restriction. Using 1 Ml-threonine, which is close to the solubility limit, we obtained a 99.9% yield ofl-homoalanine in only 3.5 h without adding external coenzymes to the cascade, giving 99.9% ee and a 29.2 g L?1h?1space-time yield. Additionally, the activities of the engineeredAtGluDH towards some other hydrophobic amino acids were also improved to 1.1-11.2 fold. Therefore, the engineering design of some dual cofactor-dependent GluDHs could not only eliminate the low catalytic activity of unnatural substrates but also enhance the cofactor utilization efficiency of these enzymes in industrial applications.
- Diao, Shiqing,Jiang, Shuiqin,Liu, Yan,Sun, Yangyang,Wang, Hualei,Wang, Liuzhu,Wei, Dongzhi
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p. 4208 - 4215
(2021/06/30)
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- Biocatalysed synthesis of chiral amines: continuous colorimetric assays for mining amine-transaminases
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In the course of our research aimed at the design of new biocatalytic processes for the enantioselective synthesis of chiral amines, we have developed new continuous assays for the screening of amine-transaminase collections. These assays are based on the use of hypotaurine as an irreversible amine donor. This β-aminosulfinic acid is converted upon transamination into 2-oxoethylsulfinic acid, which instantaneously decomposes into acetaldehyde and sulfite ions that can be easily detected by spectrophotometry using Ellman's reagent. Two complementary assays were developed based on this titration method. Firstly, a direct assay allowed detection of various transaminases able to use hypotaurine as an amino donor. In a second coupled assay,l-alanine is used as a generic donor substrate of amine-transaminases and is regenerated using an auxiliary hypotaurine-transaminase. The powerful and complementary nature of both assays was demonstrated through the screening of a collection of 549 amine-transaminases from biodiversity, thus allowing the discovery of a variety of valuable new biocatalysts for use in synthetic processes.
- Gourbeyre, Léa,Heuson, Egon,Charmantray, Franck,Hélaine, Virgil,Debard, Adrien,Petit, Jean-Louis,de Berardinis, Véronique,Gefflaut, Thierry
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p. 904 - 911
(2021/02/26)
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- FUNCTIONALIZED FLUORINE CONTAINING PHTHALOCYANINE MOLECULES
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Functionalized fluorine containing phthalocyanine molecules, methods of making, and methods of use in diagnostic applications and disease treatment are disclosed herein. In some embodiments, the fluorine containing phthalocyanine molecules are functionalized with a reactive functional group or at least one cancer-targeting ligand (CTL). The CTL can facilitate more efficient binding and/or internalization to a cancer cell than to a healthy cell. The CTL can inhibit expression of oncoprotein in some embodiments. The pthalocyanine moiety can be used in diagnostic applications, such as fluorescence labeling of a cancer cell, and/or treatment applications, such as catalyzing formation of a reactive oxygen species (ROS) which can contribute to cell death of a cancer cell.
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- Biocatalytic asymmetric synthesis of unnatural amino acids through the cascade transfer of amino groups from primary amines onto keto acids
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Flee to the hills: An unfavorable equilibrium in the amino group transfer between amino acids and keto acids catalyzed by α-transaminases was successfully overcome by coupling with a ω-transaminase reaction as an equilibrium shifter, leading to efficient asymmetric synthesis of diverse unnatural amino acids, including L-tert-leucine and D-phenylglycine. Copyright
- Park, Eul-Soo,Dong, Joo-Young,Shin, Jong-Shik
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p. 3538 - 3542
(2014/01/06)
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- Process for producing beta-1, 3-n-acetylglucosamine transferase and n-acetylglucosamine- containing composite saccharide
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The present invention can provide a process for producing a protein having β1,3-N-acetylglucosaminyltransferase activity using a transformant comprising a DNA encoding a protein having β1,3-N-acetylglucosaminyltransferase activity derived from a microorganism belonging to the genus Pasteurella and a process for producing an N-acetylglucosamine-containing complex carbohydrate using a transformant capable of producing a protein having β1,3-N-acetylglucosaminyltransferase activity derived from a microorganism.
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- METHOD OF SEARCHING SUBSTANE HAVING ANTIDIABETIC ACTIVITY
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The present invention provides a screening method of a substance which inhibits binding of a condensed purine derivative to a pancreatic β cell or a treated product of the cell, a substance which inhibits binding of a condensed purine derivative to a protein capable of the condensed purine derivative, and a substance which inhibits the expression or enzymatic activity of a protein capable of a condensed purine derivative, which comprises using the condensed purine derivative and a pancreatic β cell or a treated product of the cell or a protein capable of binding to the condensed purine derivative.
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- Process for producing alpha 2,3/ alpha 2,8-sialyltransferase and sialic acid-containing complex sugar
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The present invention can provide a process for producing a protein having α2,3/α2,8-sialyltransferase activity using a transformant comprising a DNA encoding a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism belonging to the genus Pasteurella and a process for producing a sialic acid-containing complex carbohydrate using a transformant capable of producing a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism.
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- Beta1, 3-galactose transferase and dna encoding the enzyme
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The present invention provides a protein having β1,3-galactosyltransferase activity, a DNA encoding the protein, a transformant comprising the DNA, a process for producing the protein using the transformant, and a process for producing a galactose-containing complex carbohydrate using the transformant.
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- Process for producing alpha1,4-galactosyltransferase and galactose-containing complex sugar
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The present invention can provide a process for producing a protein having α1.4-galactosyltransferase activity using a transformant comprising a DNA encoding a protein having α1.4-galactosyltransferase activity derived from a microorganism belonging to the genus Pasteurella and a process for producing a galactose-containing complex carbohydrate using a transformant capable of producing a protein having α1,4-galactosyltransferase activity derived from a microorganism.
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- Human CDR-grafted antibody and antibody fragment thereof
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A human CDR-grafted antibody or the antibody fragment thereof which specifically reacts with the extracellular region of human CC chemokine receptor 4 (CCR4) but does not react with a human blood platelet; a human CDR-grafted antibody or the antibody fragment thereof which specifically reacts with the extracellular region of CCR4 and has a cytotoxic activity against a CCR4-expressing cell; and a medicament, a therapeutic agent or a diagnostic agent comprising at least one of the antibodies and the antibody fragments thereof as an active ingredient.
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- Gene recombinant antibody and antibody fragment thereof
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A recombinant antibody or the antibody fragment thereof which specifically reacts with an extracellular domain of human CCR4; a DNA which encodes the recombinant antibody or the antibody fragment thereof; a method for producing the recombinant antibody or the antibody fragment thereof; a method for immunologically detecting CCR4, a method for immunologically detecting a cell which expressed CCR4 on the cell surface, a method for depleting a cell which expresses CCR4 on the cell surface, and a method for inhibiting production of Th2 cytokine, which comprise using the recombinant antibody according or antibody fragment thereof; a therapeutic or diagnostic agent for Th2-mediated immune diseases; and a therapeutic or diagnostic agent for a blood cancer.
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- Substituted quinoxaline-2-ones as glutamate receptor antagonists
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A novel series of substituted quinoxaline 2-ones useful as neuroprotective agents are taught. Novel intermediates, processes of preparation, and pharmaceutical compositions containing the compounds are also taught. The compounds are glutamate receptor antagonists and are useful in the treatment of stroke, cerebral ischemia, or cerebral infarction resulting from thromboembolic or hemorrhagic stroke, cerebral vasospasms, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, anoxia, seizure disorders, pain, Alzheimer's, Parkinson's, and Huntington's Diseases.
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- Peptides with an insulin-like action
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Peptides with an insulin-like action, of formula I: STR1 in which G is a hydrogen atom, an amino add residue, or a monosubstituted or polysubstituted amino acid; D is an amino acid residue, a phosphoamino acid residue, a monosaccharide residue, or a covalent bond; E is --NH--(CH2)n --NR52, a glycerol residue, or --NH--(CH2)p --R6 --R7 ; R1 is (C1 -C4)-alkyl or =O; R2 is a sulfhydryl protecting group, (C1 -C3)-alkyl, or a hydrogen atom; R3 and R4, independently of one another, are a hydrogen atom or methyl; R5, each being identical or different, is a hydrogen atom, 1 to 6 monosaccharide residues, or 1 to 6 monosubstituted or polysubstituted monosaccharide residues; R6 is O PO4 H, PO2 H, NHCOO, S or OCOO; R7 is a hydrogen atom, 1 to 6 monosaccharide residues, or 1 to 6 monosubstituted or polysubstituted monosaccharide residues; w is an integer 1 or 2; their preparation and use for treatment of diabetes mellitus or insulin-independent diabetes.
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- The asymmetric synthesis of allylglycine and other unnatural α-amino acid via zinc-mediated allylation of oximes in aqueous media
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Enantiomerically pure or highly enriched allylglycine and its chain-substituted analogs are easily accessible from the reaction of the sultam derivative of O-benzyl glyoxylic acid oxime with allylic bromides in the presence of powdered zinc in aqueous ammonium chloride.
- Hanessian, Stephen,Yang, Rui-Yang
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p. 5273 - 5276
(2007/10/03)
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- Optically active ester derivatives, preparation process thereof, liquid crystal materials and a light switching element
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Disclosed are herein optically active ester derivatives represented by the formula (I): STR1 (wherein R1 represents an alkyl group having 3 to 20 carbon atoms; R2 represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; X represents --COO-- or --OCO--; l represents a number of 1 or 2; k and m each represents a number of 0 or 1; n represents a number of 1 to 6), preparation processes therefor, liquid crystal materials containing such ester derivatives as active ingredient, and a light switching element using said liquid crystal materials as liquid crystal element.
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- Compositions for testing to predict and/or diagnose allergy to penicillins
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The invention relates to the testing of humans or other animals, such as horses, cattle or dogs, for allergic reaction or hypersensitivity to penicillins. The tests can be used both to predict and to diagnose allergy. The invention comprises new materials for use in minor determinant mixture (MDM) compositions and lyophilized, storage-stable MDM compositions and novel test methods employing such materials. The new MDM materials are N-penicilloyl amines of an aliphatic amine or α-aminoacid having the following molecular structure: STR1 wherein: R1 =a side chain which defines the type of penicillin--e.g., where R1 = STR2 the new material is a derivative of benzylpenicillin; and R2 is an alkyl group of C2 -C6 length, preferably ethyl or propyl, or an aminoacid residue as described herein. The tests are preferably carried out by applying solutions of the materials to the skin of the patient or other test animal and pricking or scratching the skin, or by injecting the materials intradermally, and then observing for wheal and flare reactions. The preferred test method comprises a two-solution test using a solution of the novel PPL preparations described in my copending U.S. Patent application Ser. No. 898,044 applied on or into one area of the patient's skin and a separate solution containing the new minor determinant material alone or as part of an MDM solution with other constituents applied on or into another area of the patient's skin.
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- Method for testing to predict and/or diagnose allergy to penicillins, and compounds and compositions for use in such tests
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The invention relates to the testing of humans or other animals, for allergic reaction or hypersensitivity to penicillins. The tests can be used both to predict and to diagnose allergy. The invention comprises new penicilloyl-polylysine (PPL) preparations, new materials for use in minor determinant mixture (MDM) compositions and novel test methods employing such materials. The new PPL preparations comprise homogeneous, high purity, maximally coupled, α-diastereoisomeric, penicilloyl conjugates of low molecular weight PPLs. The PPL materials of the invention have the molecular structure in accordance with the following generic formula: STR1 wherein: R is selected from the group consisting of H and penicilloyl groups or similar groups derived from cephalosporins or other β-lactam antibiotics; and n is an integer of from 4 to 10, at least about 66% and up to 100% of the R groups are other than hydrogen. Solutions containing this PPL material are useful in skin testing for penicillin allergy or hypersensitivity alone, but preferably are utilized in a two-part test with MDM solutions containing the novel MDM materials of the invention. The new MDM materials have the following structure: STR2 wherein: R1 = a side chain which defines the type of penicilin, the new material is a derivative of benzylpenicillin; and R2 is an alkyl group of C2 -C6 length, or an aminoacid residue as described herein. The tests are preferably carried out by applying solutions of the materials to the skin of the patient or other test animal and pricking or scratching the skin, or by injecting the materials intradermally, and then observing for wheal and flare reactions.
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- Pyrrole cephalosporin derivatives
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New pyrrole derivatives of cephalosporin compounds have been prepared which are useful as antibiotics.
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