- Specific and efficient N-propionylation of histones with propionic acid N-hydroxysuccinimide ester for histone marks characterization by LC-MS
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Histones participate in epigenetic regulation via a variety of dynamic posttranslational modifications (PTMs) on them. Mass spectrometry (MS) has become a powerful tool to investigate histone PTMs. With the bottom-up mass spectrometry approach, chemical derivatization of histones with propionic anhydride or deuterated acetic anhydride followed by trypsin digestion was widely used to block the hydrophilic lysine residues and generate compatible peptides for LC-MS analysis. However, certain severe side reactions (such as acylation on tyrosine or serine) caused by acid anhydrides will lead to a number of analytical issues such as reducing results accuracy and impairing the reproducibility and sensitivity of MS analysis. As an alternative approach, we report a novel derivatization method that utilizes N-hydroxysuccinimide ester to specifically and efficiently derivatize both free and monomethylated amine groups in histones. A competitive inhibiting strategy was implemented in our method to effectively prevent the side reactions. We demonstrated that our method can achieve excellent specificity and efficiency for histones derivatization in a reproducible manner. Using this derivatization method, we succeeded to quantitatively profile the histone PTMs in KMS11 cell line with selective knock out of translocated NSD2 allele (TKO) and the original parental KMS11 cell lines (PAR) (NSD2, a histone methyltransferase that catalyzes the histone H3 K36 methylation), which revealed a significant crosstalk between H3 protein K27 methylation and adjacent K36 methylation.
- Liao, Rijing,Wu, Haiping,Deng, Haibing,Yu, Yanyan,Hu, Min,Zhai, Huili,Yang, Pengyuan,Zhou, Shaolian,Yi, Wei
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Read Online
- PCR incorporation of dUMPs modified with aromatic hydrocarbon substituents of different hydrophilicities: Synthesis of C5-modified dUTPs and PCR studies using Taq, Tth, Vent (exo-) and Deep Vent (exo-) polymerases
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Deoxyuridine triphosphate derivatives (dUTPs) modified at the C5 position of the pyrimidine ring with various aromatic hydrocarbon substituents of different hydrophilicities have been synthesized. The aromatic hydrocarbon substituents were attached to dUTPs via a CH[dbnd]CH[sbnd]CH2[sbnd]NHCO[sbnd]CH2 linker. The efficiency of the PCR incorporation of modified dUMPs using Taq, Tth, Vent (exo-) and Deep Vent (exo-) polymerases and a model DNA template containing one, two and three adjacent adenine nucleotides at three different sites within the sequence was investigated. For all the polymerases used, the yield of the modified PCR product was significantly increased with increasing hydrophilicity of the aromatic hydrocarbon substituent. In particular, for the above polymerases, the efficiency of the incorporation of dUMPs modified with the most hydrophilic of the studied aromatic hydrocarbon substituents, a 4-hydroxyphenyl residue, was 60–85% of the efficiency of dTMP incorporation. At the same time, the relative efficiencies of the incorporation of dUMPs modified with 2-, 4-methoxyphenyl, phenyl and 4-nitrophenyl substituents ranged from 20 to 50% and were 2–18% for the 1-naphthalene and 4-biphenyl groups, which were the most hydrophobic of the studied aromatic hydrocarbon substituents.
- Chudinov, Alexander V.,Kuznetsova, Viktoriya E.,Miftakhov, Rinat A.,Shershov, Valeriy E.,Surzhikov, Sergey A.,Yurasov, Dmitry A.,Zasedateleva, Olga A.
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supporting information
(2020/04/17)
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- N?-Acryloyllysine Piperazides as Irreversible Inhibitors of Transglutaminase 2: Synthesis, Structure-Activity Relationships, and Pharmacokinetic Profiling
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Transglutaminase 2 (TGase 2)-catalyzed transamidation represents an important post-translational mechanism for protein modification with implications in physiological and pathophysiological conditions, including fibrotic and neoplastic processes. Consequently, this enzyme is considered a promising target for the diagnosis of and therapy for these diseases. In this study, we report on the synthesis and kinetic characterization of N?-acryloyllysine piperazides as irreversible inhibitors of TGase 2. Systematic structural modifications on 54 new compounds were performed with a major focus on fluorine-bearing substituents due to the potential of such compounds to serve as radiotracer candidates for positron emission tomography. The determined inhibitory activities ranged from 100 to 10?000 M-1 s-1, which resulted in comprehensive structure-activity relationships. Structure-activity correlations using various substituent parameters accompanied by covalent docking studies provide an advanced understanding of the molecular recognition for this inhibitor class within the active site of TGase 2. Selectivity profiling of selected compounds for other transglutaminases demonstrated an excellent selectivity toward transglutaminase 2. Furthermore, an initial pharmacokinetic profiling of selected inhibitors was performed, including the assessment of potential membrane permeability and liver microsomal stability.
- Wodtke, Robert,Hauser, Christoph,Ruiz-Gómez, Gloria,J?ckel, Elisabeth,Bauer, David,Lohse, Martin,Wong, Alan,Pufe, Johanna,Ludwig, Friedrich-Alexander,Fischer, Steffen,Hauser, Sandra,Greif, Dieter,Pisabarro, M. Teresa,Pietzsch, Jens,Pietsch, Markus,L?ser, Reik
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supporting information
p. 4528 - 4560
(2018/05/07)
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- Highly efficient and selective biocatalytic production of glucosamine from chitin
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N-Acetyl glucosamine (GlcNAc) is one of the most abundant biomolecules on Earth and is cheaply available from chitin, a major component of crustaceans. The key step in the conversion of GlcNAc to high-value products is the de-N-acetylation to glucosamine, in itself a valuable dietary supplement that is produced at over 29:000 tons scale per annum by chemical hydrolysis, a process that requires harsh reaction conditions and leads to side products requiring separation. Here, we report for the first time the isolation and characterisation of an enzyme, a deacetylase from Cyclobacterium marinum that is able to catalyse the highly selective quantitative hydrolysis of GlcNAc to glucosamine under mild reaction conditions. This enzyme is small (38 kDa), is easily obtainable by heterologous expression in E. coli, has high turnover rates (kcat=61 s-1), tolerates high substrate concentrations (over 100 g L-1) and can be repeatedly re-used as an immobilised catalyst. When coupled with chitinase, the high selectivity of the enzyme for GlcNAc over other biomolecules allowed one-pot extraction of glucosamine from crude solid mushroom fractions containing chitin, thus allowing for alternative production of glucosamine from non-animal sources, of benefit to consumers with crustacean allergies and vegan diets. We suggest that the deacetylase fills an important gap in the sustainable exploitation of GlcNAc and chitin.
- Lv,Laborda,Huang,Cai,Wang,Lu,Doherty,Liu,Flitsch,Voglmeir
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supporting information
p. 527 - 535
(2017/08/15)
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- Nitroimidazole conjugates of bis(thiosemicarbazonato)64Cu(II) - Potential combination agents for the PET imaging of hypoxia
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Combination agents comprising two different pharmacophores with the same biological target have the potential to show additive or synergistic activity. Bis(thiosemicarbazonato)copper(II) complexes (e.g. 64Cu-ATSM) and nitroimidazoles (e.g. 18F-MISO) are classes of tracer used for the delineation of tumor hypoxia by positron emission tomography (PET). Three nitroimidazole-bis(thiosemicarbazonato)copper(II) conjugates were produced in order to investigate their potential as combination hypoxia imaging agents. Two were derived from the known bifunctional bis(thiosemicarbazone) H2ATSM/A and the third from the new precursor diacetyl-2-(4-N-methyl-3-thiosemicarbazone)-3-(4-N-ethylamino-3-thiosemicarbazone) - H2ATSM/en. Oxygen-dependent uptake studies were performed using the 64Cu radiolabelled complexes in EMT6 carcinoma cells. All the complexes displayed appreciable hypoxia selectivity, with the nitroimidazole conjugates displaying greater selectivity than a simple propyl derivative used as a control. Participation of the nitroimidazole group in the trapping mechanism is indicated by the increased hypoxic uptake of the 2- vs. the 4-substituted 64Cu-ATSM/A derivatives. The 2-nitroimidazole derivative of 64Cu-ATSM/en demonstrated superior hypoxia selectivity to 64Cu-ATSM over the range of oxygen concentrations tested. Biodistribution of the radiolabelled 2-nitroimidazole conjugates was carried out in EMT6 tumor-bearing mice. The complexes showed significantly different uptake trends in comparison to each other and previously studied Cu-ATSM derivatives. Uptake of the Cu-ATSM/en conjugate in non-target organs was considerably lower than for derivatives based on Cu-ATSM/A.
- Bonnitcha, Paul D.,Bayly, Simon R.,Theobald, Mark B.M.,Betts, Helen M.,Lewis, Jason S.,Dilworth, Jonathan R.
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experimental part
p. 126 - 135
(2012/01/13)
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- Selective [15Nη2] labelling of an NG-propionylated arginine derivative
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A straightforward convergent synthesis of [15N η2]-Bz-Arg(Nη-propionyl)-OEt*TFA is presented. In this approach, the guanidinylation reagent [15N 2]-N(boc)-N′(propionyl)-S-methylisothiourea is reacted with the side chain amino group of the title compound's ornithine precursor. The guanidinylation step is promoted by stoichiometric addition of HgCl2 to force completion. This method leads directly to the NG-acylated product and the acyl residue is principally modifiable in the last synthetic step of the guanidinylation reagent. Copyright
- Kleinmaier, Roland,Gschwind, Ruth M.
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experimental part
p. 29 - 32
(2009/10/23)
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- Guanidine-acylguanidine bioisosteric approach in the design of radioligands: Synthesis of a tritium-labeled NG-propionylargininamide ([3H]-UR-MK114) as a highly potent and selective neuropeptide Y Y1 receptor antagonist
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Synthesis and characterization of (R)-Nα-(2,2- diphenylacetyl)-N-(4-hydroxybenzyl)-Nω-([2,3- 3H]-propanoyl)-argininamide ([3H]-UR-MK114), an easily accessible tritium-labeled NPY Y1 receptor (Y1R) antagonist (KB: 0.8 nM, calcium assay, HEL cells) derived from the (R)-argininamide BIBP 3226, is reported. The radioligand binds with high affinity (KD, saturation: 1.2 nM, kinetic experiments: 1.1 nM, SK-N-MC cells) and selectivity for Y1R over Y2, Y 4, and Y5 receptors. The title compound is a useful pharmacological tool for the determination of Y1R ligand affinities, quantification of Y1R binding sites, and autoradiography.
- Keller, Max,Pop, Nathalie,Hutzler, Christoph,Beck-Sickinger, Annette G.,Bernhardt, Günther,Buschauer, Armin
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supporting information; experimental part
p. 8168 - 8172
(2009/12/07)
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- Mucoscal vaccine and methods for using the same
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The present invention relates to compositions and methods for stimulating enhanced mucosal immune responses in vivo. Particularly, the present invention relates to lipid-nucleic acids (“LNA”) formulations and methods of using thereof for stimulating enhanced mucosal immune responses in mammals. More particularly, the present invention relates to improved mucosal vaccines comprising target antigens associated with LNA formulations and methods of using thereof that stimulate antigen-specific mucosal immune responses in mammals.
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- Photoactivatable peptides based on BMS-197525: A potent antagonist of the human thrombin receptor (PAR-1)
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Photoactivatable analogs of the human thrombin receptor (PAR-1) antagonist, N-trans-cinnamoyl-p-fluoroPhe-p-guandinoPhe-Leu-Arg-NH2 (BMS- 197525), were prepared with benzophenone substitutions in the N-terminal, Leu, or Arg position. The analogs retained antagonist activity (with reduced potency); the tritium-labeled isotopomers are potential photoaffinity labels for the receptor. C-Terminal extension of the analogs with ornithine(biotin) did not significantly alter antagonist potency.
- Elliott, John T.,Hoekstra, William J.,Maryanoff, Bruce E.,Prestwich, Glenn D.
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p. 279 - 284
(2007/10/03)
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- REACTIVITY OF N-HYDROXYSUCCINIMIDE ESTERS
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The reactions of N-hydroxysuccinimide esters (OSu-esters) of benzyloxycarbonylamino acids and of simple carboxylic acid with p-anisidine in DMSO were studied kinetically at various temperatures.Activation parameters ΔH++ and ΔS++ for these data were determined.The rate constants for aminolysis of carboxylic acid esters fit the two-parameter Taft equation with reaction constants equal: ρ* = 1.08 and ρs = 1.1.The activation entropies are in the range -121.8 - -180.0 J/deg M.Transition state in these reactions is tetrahedral and zwitter ionic, in agreementwith the mechanism given by Cline and Hanna for aminolysis of succinimidyl benzoates.
- Stefanowicz, P.,Siemion, I. Z.
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p. 111 - 118
(2007/10/02)
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