The Experts below are selected from a list of 80607 Experts worldwide ranked by ideXlab platform
Tairo Oshima - One of the best experts on this subject based on the ideXlab platform.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
Katsumi Kakinuma - One of the best experts on this subject based on the ideXlab platform.
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novel Substrate Specificity of designer 3 isopropylmalate dehydrogenase derived from thermus thermophilus hb8
Bioscience Biotechnology and Biochemistry, 2001Co-Authors: Masaaki Fujita, Hideyuki Tamegai, Tadashi Eguchi, Katsumi KakinumaAbstract:Redesigning of an enzyme for a new catalytic reaction and modified Substrate Specificity was exploited with 3-isopropylmalate dehydrogenase (IPMDH). Point-mutation on Gly-89, which is not in the catalytic site but near it, was done by changing it to Ala, Ser, Val, and Pro, and all the mutations changed the Substrate Specificity. The mutant enzymes showed higher catalytic efficiency (kcat/Km) than the native IPMDH when malate was used as a Substrate instead of 3-isopropylmalate. More interestingly, an additional insertion of Gly between Gly-89 and Leu-90 significantly altered the Substrate-Specificity, although the overall catalytic activity was decreased. Particularly, this mutant turned out to efficiently accept D-lactic acid, which was not accepted as a Substrate by wild-type IPMDH at all. These results demonstrate the opportunity for creating novel enzymes by modification of amino acid residues that do not directly participate in catalysis, or by insertion of additional residues.
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overproduction and Substrate Specificity of 3 isopropylmalate dehydrogenase from thiobacillus ferrooxidans
Bioscience Biotechnology and Biochemistry, 1998Co-Authors: Hideyuki Matsunami, Katsumi Kakinuma, Tadashi Eguchi, Kenji Inagaki, Hiroshi Kawaguchi, Hidehiko TanakaAbstract:We constructed an overexpression system in Escherichia coli of the leuB gene coding for 3-isopropylmalate dehydrogenase in Thiobacillus ferrooxidans. E. coli harboring the plasmid we constructed, pKK leuB1, produced 17-fold the enzyme protein of the expression system previously used for purification. The Substrate Specificity of the enzyme was analyzed with synthetic (2R, 3S)-3-alkylmalates. The 3-isopropylmalate dehydrogenase of Thiobacillus ferrooxidans had broad Specificity toward the alkylmalates.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
Kentaro Miyazaki - One of the best experts on this subject based on the ideXlab platform.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
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kinetic analysis on the Substrate Specificity of 3 isopropylmalate dehydrogenase
FEBS Letters, 1993Co-Authors: Kentaro Miyazaki, Hiroaki Terasawa, Katsumi Kakinuma, Tairo OshimaAbstract:Abstract Substrate Specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a Substrate, implying a broad Substrate Specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal mol , the rather small value supporting the broad Specificity. Although the enzyme shows a broad Specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.
David R. Liu - One of the best experts on this subject based on the ideXlab platform.
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Phage-assisted continuous evolution of proteases with altered Substrate Specificity
Nature Communications, 2017Co-Authors: Michael S. Packer, Holly A. Rees, David R. LiuAbstract:Proteases are promising therapeutics to treat diseases such as hemophilia which are due to endogenous protease deficiency. Here the authors use phage-assisted continuous evolution to evolve a variant TEV protease with altered target peptide sequence specificities. Here we perform phage-assisted continuous evolution (PACE) of TEV protease, which canonically cleaves ENLYFQS, to cleave a very different target sequence, HPLVGHM, that is present in human IL-23. A protease emerging from ∼2500 generations of PACE contains 20 non-silent mutations, cleaves human IL-23 at the target peptide bond, and when pre-mixed with IL-23 in primary cultures of murine splenocytes inhibits IL-23-mediated immune signaling. We characterize the Substrate Specificity of this evolved enzyme, revealing shifted and broadened Specificity changes at the six positions in which the target amino acid sequence differed. Mutational dissection and additional protease Specificity profiling reveal the molecular basis of some of these changes. This work establishes the capability of changing the Substrate Specificity of a protease at many positions in a practical time scale and provides a foundation for the development of custom proteases that catalytically alter or destroy target proteins for biotechnological and therapeutic applications.
Dewey G. Mccafferty - One of the best experts on this subject based on the ideXlab platform.
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Sortase transpeptidases: insights into mechanism, Substrate Specificity, and inhibition.
Biopolymers, 2010Co-Authors: Kathleen W. Clancy, Jeffrey A. Melvin, Dewey G. MccaffertyAbstract:Gram-positive bacteria pose a serious healthcare threat. The growing antibiotic resistance epidemic creates a dire need for new antibiotic targets. The sortase family of enzymes is a promising target for antimicrobial therapy. This review covers the current knowledge of the mechanism, Substrate Specificity, and inhibitory studies of the Gram-positive bacterial [corrected] enzyme sortase.
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analysis of the Substrate Specificity of the staphylococcus aureus sortase transpeptidase srta
Biochemistry, 2004Co-Authors: Ryan G Kruger, Balint Otvos, Brenda A Frankel, Matthew L Bentley, Patrick Dostal, Dewey G. MccaffertyAbstract:The Staphylococcus aureus sortase transpeptidase SrtA isoform is responsible for the covalent attachment of virulence and colonization-associated proteins to the bacterial peptidoglycan. SrtA utilizes two Substrates, undecaprenol-pyrophosphoryl-MurNAc(GlcNAc)-Ala-d-isoGlu-Lys(e-Gly5)-d-Ala-d-Ala (branched Lipid II) and secreted proteins containing a highly conserved C-terminal LPXTG sequence. SrtA simultaneously cleaves the Thr−Gly bond of the LPXTG-containing protein and forms a new amide bond with the nucleophilic amino group of the Gly5 portion of branched Lipid II, anchoring the protein to this key intermediate that is subsequently polymerized into peptidoglycan. Here we describe the development of a general in vitro method for elucidating the Substrate Specificity of sortase enzymes. In addition, using immunofluorescence, cell adhesion assays, and transmission electron microscopy, we establish links between in vitro Substrate Specificity and in vivo function of the S. aureus sortase isoforms. Results...
