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Showing 1 to 20 of 55 for “"thioester"”.
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Dipole - Stabilized Carbanions From a Methylamide and a Methyl Thioester
Made available in DSpace on 2014-12-10T23:02:03Z (GMT). No. of bitstreams: 1 7511572.pdf: 4835541 bytes, checksum: a8b2da654fbeed093665fa20b6b7c27a (MD5) Previous issue date: 1974
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Mechanisms of Non-Enzymatic Peptide Bond Formation: Thioester and Transamidation Routes
… under mild prebiotic conditions during both the thioester-based production of phenylalanine peptides and peptidyl thioesters, and the spontaneous cyclization of glutamine t-butyl ester (Gln-tbe) into pyroglutamic acid t-butyl ester. Internal standard-based quantitative MS determined that 4.9 x …
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Mass Spectrometric Interrogation of Thioester-Bound Intermediates on Nonribosomal Peptide and Polyketide Assembly Lines
Innovative developments in MS continue to increase the complexity of biological systems amenable for study and provide exciting research opportunities at interdisciplinary boundaries. The doctoral studies presented here have furthered the understanding of the biosynthesis of key natural products …
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Synthetically Useful Dipole-Stabilized Carbanions From Thioesters and Thiocarbamates
… formation of dipole-stabilized carbanions from thioesters, deprotonation of a tertiary center at the carbon adjacent to the sulfur of a thioester was found for the first time. Isopropyl, 2-octyl, and 4-tert-butylcyclohexyl 2,4,6-triisopropylthiobenzoates react with sec-butyllithium/TMEDA at …
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Mechanistic Studies of the Activation of Ubiquitin-Conjugating Enzymes by Ring-Type Ubiquitin Ligases
… enzymes (E1) activate ubiquitin and form thioester linkages with ubiquitin, which are then transferred onto ubiquitin-conjugating enzymes (E2). Ubiquitin-conjugating enzymes, with the help of ubiquitin ligases (E3) transfer ubiquitin onto ubiquitination targets to form isopeptide linkages …
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A comparative genomics approach towards classifying immunity-related proteins in the tsetse fly
… genomics approach. In this study we characterize thioester-containing proteins (TEPs), a sub-family of immunity-related proteins, in Glossina by leveraging the EST data for G.morsitans and the genomic resources of D. melanogaster, A. gambiae as well as A.aegypti.A total of 17 TEPs corresponding to …
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Substrate elucidation and mutasynthesis: Characterisation of the biosynthetic pathway of a tripyrrolic secondary metabolite, prodigiosin
… N-terminal one, which we propose is a thioester reductase that converts a 3-acetyloctanoyl thioester to 3-acetyloctanal. Attempted chemical complementation of a pigD-knockout strain of Serratia using synthetic thioester, carboxylic acid and aldehyde substrates showed that both the …
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Identification and Characterization of a New E1 That Activates Ubiquitin and FAT10
… reactions. E1-L2, but not E1 or E1-L1, forms a thioester with FAT10 in vitro. The formation of the thioester bond requires the active site cysteine residue of E1-L2 and the C-terminal diglycine motif of FAT10. In addition, endogenous FAT10 forms a thioester with E1-L2 in cells stimulated with …
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Molekularbiologische Gewinnung von RNase 40-124 Fragmenten zur Synthese von einheitlichen Glycoproteinen durch native chemische Ligation
… Dazu sollte die chemoselektive Reaktion von Thioestern und molekularbiologisch gewonnenen Fragmenten mit N-terminalem Cys über die native chemische Ligation (NCL) ausgenutzt werden. Diese Methode sollte mit dem Modellprotein Ribonuclease 1-124 entwickelt werden. Zur Synthese der RNase durch …
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Antibiotic-free PHA-based antibacterial materials for bone regeneration
… first strategy, inherently antibacterial PHAs, thioester containing PHAs, were produced by bacterial fermentation. Such materials exhibited antibacterial activity by contact against S. aureus 6538P. Physical blending of thioester-PHA with P(3HHx-co-3HO-co-3HD) was investigated and a polymer …
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Solid-supported synthesis of peptidoglycan fragments and their biological evaluation
… are supported by an enzymatic study using the thioesterase activity of the R39 peptidase on (R)-S2d. Because of the specific affinity for the R enantiomer of thioesters, the enantioselective synthesis of (R)-S2d is described that makes use of the coupling agent T3P. A chromatographic method is …
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Synthesis Of Alkylthiol-containing Fluorene Derivatives For Gold Nanoparticle Functionalization
… atom on the alkyl chains was converted to thioester by reaction with potassium thioacetate. This was followed by the hydrolysis of the thioester to form the thiol moiety. The compounds synthesized were characterized using 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and …
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Cyclization modes in type III polyketide synthases and the synthetic compounds used as probes for mechanistic studies.
… that aldol cyclization of the linear tetraketide thioester intermediate (15) precedes the hydrolysis of 15 in the ArsB catalyzed resorcinol ring formation. 3,5-Dioxooctanoic acid 32a was also synthesized in order to probe the lactonization mechanism in type III PKSs such as PpASCL and AthPKSA. It …
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Biotin synthesis in Escherichia coli
… pathway. The ω-carboxyl group of a malonyl-thioester precursor is methylated by BioC, as an initiation step in biotin synthesis. The shielding by a methyl ester moiety is required for recognition and chain elongation of this atypical substrate by the fatty acid synthetic enzymes. The …
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Biotin synthesis in Bacillus subtilis
… in the first stage of synthesis of a pimelate thioester moiety. Bacillus subtilis represents a group of microorganisms that follow a different pathway for biotin synthesis. Genetic and biochemical studies identified bioW and bioI as two genes required for pimeloyl-CoA and pimeloyl-ACP …
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Acyclic Imidate and Thiomidate Normal-Oxides: Nitrones of Esters and Thioesters (alpha-Alkoxynitrones, Alpha-Alkylthionitrones, Normal - Alkylthiohydroxamic Acids, X-Ray)
… The E/Z stereochemistry of the C-phenyl thioester nitrones is unambiguously established on the basis of an X-ray structural analysis on the N,S-dimethyl compound, and that of the C-alkyl counterparts is tentatively assigned on the basis of long range coupling, nuclear Overhauser effects, …
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Studies on the biosynthesis of oudenone and verucopeptin
… incubation of 2 H-labeled, N -acetylcysteamine thioester derivative of 70 with growing cultures of Oudemansiella radicata . The proposed mechanism for the cyclization of 70 into 67 is analogous to the "polyepoxide cascade" model, which has been previously implicated in the biosynthesis of …
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Design and Synthesis of an E3 ligase Activity-Based Probe and its Application for the Discovery of a New Class of E3 Ligase
… residues which relay the Ub to substrate via two thioester intermediates (RING-Cys-Relay, RCR). This discovery demonstrates the power and potential of our E3 activity based protein profiling (ABPP) system.
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Sintesi di molecole organiche enantiomericamente arricchite con l'uso della catalisi organica
… first matter is about the synthesis of α-amino thioester derivatives through a tandem condensation-intramolecular rearrangement-protonation, this is a conceptually novel chiral Brønsted base/ Brønsted acid catalytic method that provides a number of important synthetic building blocks in good …
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