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Brauc Sigrid - - 2011
Arabidopsis possesses several genes encoding aspartate aminotransferase, which catalyzes the bidirectional conversion of aspartate into glutamate. These amino acids together with asparagine and glutamine play an important role in N storage and distribution. In addition, they act as precursors for other amino acids. The gene encoding cytosolic aspartate aminotransferase, Asp2, ...
Zhang Wei - - 2011
An improved synthesis of (2S, 4S)- and (2S, 4R)-2-amino-4-methyldecanoic acids was accomplished using a glutamate derivative as starting material and Evans' asymmetric alkylation as the decisive step. The NMR data of the two diastereomers were measured and compared with those of the natural product. As a result, the stereochemistry of ...
Moradi Mahmoud - - 2011
There has been considerable debate about the intrinsic PPII propensity of amino acid residues in denatured polypeptides. Experimentally, this scale is based on the behavior of guest amino acid residues placed in the middle of proline-based hosts. We have used classical molecular dynamics simulations combined with replica exchange methods in ...
Yong Xiaoyu - - 2011
Poly-γ-glutamic acid (γ-PGA) is a polymer with uses in foods, cosmetics, medicine and agriculture. The medium for the production of γ-PGA by Bacillusamyloliquefaciens C1 was optimized by response surface methodology using agro-industrial wastes in solid-state fermentation (SSF). The optimal SSF medium (20g substrates with 50% initial moisture) for producing γ-PGA ...
Melø Torun M - - 2011
Evaluating early changes in cerebral metabolism in hydrocephalus can help in the decision making and the timing of surgical intervention. This study was aimed at examining the tricarboxylic acid (TCA) cycle rate and (13)C label incorporation into neurotransmitter amino acids and other compounds 2 weeks after rats were subjected to ...
Castro-Coronel Yaneth - - 2011
Chronic exposure to inorganic arsenic severely damages the central nervous system. Glutamate is the major excitatory amino acid, and is highly neurotoxic when levels in the synaptic cleft are not properly regulated by a family of Na(+)-dependent excitatory amino acid transporters. Within the cerebellum, the activity of the Bergmann glia ...
Chen Y-C - - 2011
Lychee (Litchi chinensis Sonn.) flower is a major nectar source in Taiwan. Antioxidant activities of acetone, ethanol, and hot-water extracts of the flower were estimated through three biochemical models: inhibition of Cu(2+) -induced oxidation of human low-density lipoprotein, scavenging ability of oxygen radicals in human blood, and inhibition of human erythrocyte ...
Musto Alberto E - - 2011
Temporal lobe epilepsy, one of the most common epilepsy syndromes, is characterized by hippocampal hyperexcitability and progressive seizure susceptibility. Omega-3 fatty acids are involved in neuronal excitability and have anticonvulsant properties. We studied the effect of docosahexaenoic acid (DHA) or its derived lipid mediator, neuroprotectin D1 (NPD1, 10R,17S-dihydroxy-docosa-4Z,7Z,11E,13E,15Z,19Z-hexaenoic acid), in ...
Innis Sheila M - - 2011
Human milk TG are a remarkable example of stereo-specific positioning of fatty acids with structures that are highly conserved and unusual. Not only does human milk contain high amounts of fat and 16:0, but ~70% of the 16:0 is esterified at the TG stereo-specifically numbered (sn)-2 position, with preferential positioning ...
Samartsev V N - - 2011
In liver mitochondria fatty acids act as protonophoric uncouplers mainly with participation of internal membrane protein carriers - ADP/ATP and aspartate/glutamate antiporters. In this study the values of recoupling effects of carboxyatractylate and glutamate (or aspartate) were used to assess the degree of participation of ADP/ATP and aspartate/glutamate antiporters in uncoupling ...
Kravtsov A A - - 2011
We demonstrated an increase in glutamate neurocytotoxicity in cultured cerebellar cells from rat pups subjected to lead poisoning during the prenatal development or early lactation period. The toxic effect of glutamate was weaker, if lead was applied in combination with antioxidant comenic acid. These data are discussed in view of ...
Yi Peng - - 2011
Due to lack of country-specific norms in China, we established the reference range of plasma amino acids for younger Chinese children by reverse phase high-performance liquid chromatography (HPLC). Plasma proteins were precipitated with ethanol. L-Norvaline served as an internal standard. This HPLC method was based on automated precolumn derivatization using ...
Kim So-Hyun - - 2011
Guava leaves were classified and the free radical scavenging activity (FRSA) evaluated according to different harvest times by using the (1)H-NMR-based metabolomic technique. A principal component analysis (PCA) of (1)H-NMR data from the guava leaves provided clear clusters according to the harvesting time. A partial least squares (PLS) analysis indicated ...
Uneyama Hisayuki - - 2011
Recent evidence indicates that free amino acids are nutrients as well as acting as chemical transmitters within the gastrointestinal tract. Gut glutamate research is the most advanced among 20 amino acids. Free glutamate carries the umami taste sensation on the tongue and a visceral sensation in the gut, especially the ...
Liu Xiaoli - - 2011
The Manila clam (Ruditapes philippinarum) has been considered a good sentinel species for metal pollution monitoring in estuarine tidal flats. Along the Bohai coast of China, there are dominantly distributed three species of clams (White, Liangdao Red and Zebra in Yantai population) endowed with distinct tolerances to environmental stressors. In ...
Wu Sangwook - - 2010
We investigate the post-translational generation of Gla (γ-carboxy glutamic acid) from Glu (glutamic acid) by vitamin K carboxylase (VKC) in solvent. VKC is thought to convert vitamin K, in the vitamin K cycle, to an alkoxide-epoxide form, which then reacts with CO(2) to generate an essential ingredient in blood coagulation, ...
Somarajan Sudha R - - 2010
We identified Mpn133 as a Ca(2+)-dependent cytotoxic nuclease of Mycoplasma pneumoniae. Flow cytometry analysis and immunofluorescence studies revealed the binding and internalization of recombinant Mpn133 (rMpn133) in human airway A549 cells. Amino acid sequence comparisons of Mpn133 with other mycoplasma nucleases demonstrated the presence of a unique glutamic acid-, lysine- ...
Kino Kuniki - - 2010
L-Amino acid ligase (EC 6.3.2.28) is a microbial enzyme catalyzing formation of an alpha-peptide bond from unprotected L-amino acids in an ATP-dependent manner. The YwfE protein from Bacillus subtilis 168 was the first reported L-amino acid ligase, and it synthesizes various dipeptides. Thereafter, several L-amino acid ligases were newly obtained ...
Hancock Susan M SM Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, - - 2010
We report the discovery of a simple system through which variant pyrrolysyl-tRNA synthetase/tRNA(CUA Pyl) pairs created in Escherichia coli can be used to expand the genetic code of Saccharomyces cerevisiae. In the process we have solved the key challenges of producing a functional tRNA(CUA Pyl) in yeast and discovered a ...
Kiesewetter Dale O - - 2011
The automated radiochemical synthesis of N-[2-(4-[(18)F]fluorobenzamido)ethyl]maleimide ([(18)F]FBEM, IUPAC name: N-maleoylethyl-4-[(18)F]fluorobenzamide), a prosthetic group for radiolabeling the free sulfhydryl groups of peptides and proteins, is herein described. 4-[(18)F]fluorobenzoic acid was first prepared by nucleophilic displacement of a trimethylammonium moiety on a pentamethylbenzyl benzoate ester with [(18)F]fluoride. In the second step the ...
Katritzky Alan R - - 2010
Benzotriazol-1-yl-sulfonyl azide, a new crystalline, stable, and easily available diazotransfer reagent provides N-(α-azidoacyl)benzotriazoles convenient for N-, O-, C- and S-acylations. The efficient syntheses of various amides, azido protected peptides, esters, ketones and thioesters is reported together with a wide range of azides (including α-azido acids from α- amino acids in ...
Cho Joon-il - - 2010
In sharp contrast with helical polypeptides carrying basic side chains, Api(8), a basic oligopeptide containing the non-natural achiral amino acid 4-aminopiperidine-4-carboxylic acid (Api), adopts a helical conformation only in acidic media. Alkaline titration of a protonated Api(8) oligomer appended with a leucine derivative at its N-terminus showed that disruption of ...
Gredicak Matija - - 2010
Enediyne-peptide conjugates are recently recognized as useful tools in targeting various proteins, while the mechanism underlying the observed activity remains somewhat unclear. Addressing these issues, we have prepared acyclic amino acid derived enediynes and disclosed a novel thermally induced cyclization-elimination pathway. Initial formation of 1,4-benzene diradical and H-atom abstraction from ...
Kuhn Sebastian M - - 2010
We describe a strategy for the rapid selection of mutant aminoacyl-tRNA synthetases (aaRS) with specificity for a novel amino acid based on fluorescence-activated cell sorting of transformed Escherichia coli using as reporter the enhanced green fluorescent protein (eGFP) whose gene carries an amber stop codon (TAG) at a permissive site ...
Bonnard Vanessa - - 2010
Based on a split-and-mix strategy, a library of trimeric Polyamide Amino Acids (PAA) incorporating four different amino acids (Lys, Ala, Arg, and Phe) has been prepared. Screening of the batches for HIV TAR RNA binding in a fluorescent assay allowed the identification of several components that interact with TAR RNA ...
Katritzky Alan R - - 2010
Novel N-(Cbz-aminoacyl)thiosemicarbazides 3a-c were cyclized by treatment with sulfuric acid to give 1,3,4-thiadiazoles 4a-c. Compounds 4a-c reacted with N-(Cbz-aminoacyl)- and -dipeptidoylbenzotriazoles to afford chirally pure 1,3,4-thiadiazol-2-yl-substituted amino acids 6a-c and dipeptides 7a-c.
Meyer Falco-Magnus - - 2010
Functionalized alpha-amino acid building blocks have been prepared in good yield with high regiocontrol and preservation of stereochemistry via iridium-catalyzed borylation of suitably protected aromatic alpha-amino acid derivatives. The utility of these systems in peptide couplings and Suzuki reactions has been demonstrated.
Duffy Noah H NH Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, - - 2010
Nonsense codon suppression for unnatural amino acid incorporation requires the preparation of a suppressor aminoacyl-tRNA. Chemical acylation strategies are general but inefficient and arduous. A recent report (J. Am. Chem. Soc. 2007, 129, 15848) showed acylation of RNA mediated by lanthanum(III) using amino acid phosphate esters. The successful implementation of ...
Chen Xin - - 2011
To prevent potential errors in protein synthesis, some aminoacyl-transfer RNA (tRNA) synthetases have evolved editing mechanisms to hydrolyze misactivated amino acids (pre-transfer editing) or misacylated tRNAs (post-transfer editing). Class Ia leucyl-tRNA synthetase (LeuRS) may misactivate various natural and non-protein amino acids and then mischarge tRNA(Leu). It is known that the ...
Brackley Chris A - - 2010
The advance of particles in many driven diffusion systems depends on the availability of resources in the surrounding environment. In the balance between supply and demand of such resources we are confronted with a regime in which, under limited resource availability, the flow is markedly reduced. In the context of ...
Rodríguez-Hernández Annia A Department of Chemistry and Biochemistry and Interdepartmental Program in Biomolecular Science and Engineering, University of California, Santa Barbara, California 93106-9510, - - 2010
A protein engineering approach to delineating which distinct elements of homologous tRNA synthetase architectures are responsible for divergent RNA-amino acid pairing specificities is described. Previously, we constructed a hybrid enzyme in which 23 amino acids from the catalytic domain of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) were replaced with the corresponding ...
Perekalin Dmitry S - - 2010
The interaction of [Ru(eta(6)-C(10)H(8))(Cp)](+) (Cp=C(5)H(5)) with aromatic amino acids (L-phenylalanine, L-tyrosine, L-tryptophane, D-phenylglycine, and L-threo-3-phenylserine) under visible-light irradiation gives the corresponding [Ru(eta(6)-amino acid)(Cp)](+) complexes in near-quantitative yield. The reaction proceeds in air at room temperature in water and tolerates the presence of non-aromatic amino acids (except those which are sulfur ...
Moccia Maria - - 2010
A novel nucleic acid compaction device based on a positively-charged alpha,epsilon-poly-l-lysine was realized for the first time. The polycationic peptide was obtained by assembling Fmoc and Boc orthogonally protected l-lysine monomers by solid phase synthesis. The route to the novel polycation is very fast and convenient because it allows for ...
Bayryamov Stanislav G - - 2010
Bz(NO(2))-Orn(Boc)-OCH(2)CN was synthesized as an amino acid component with effective and successful orthogonal protection for amino acylation of 5'-O-Pivaloyl nucleosides and preparation of substrates for model ribosome reactions. The synthesis was carried out using suitable combinations of the methods of peptide synthesis and modification of amino acids.
Ohtsuki Takashi - - 2010
We present three methods relating to tRNA aminoacylation with non-natural amino acids using an Escherichia coli EF-Tu E215A/D216A mutant that can bind tightly to aa-tRNAs carrying either non-natural or natural amino acids: (i) a method for improving aminoacylation efficiency, (ii) a rapid method for analysing aminoacylation efficiency without the use ...
Munegumi Toratane - - 2010
Several types of L-amino acid residues (Ser, Asp) in proteins are sometimes converted to D-amino acid residues by posttranslational isomerization. This phenomenon leads to an increase in hydrophobicity and results in their deposition from aqueous media. This research involves the hydrophobicity of oligopeptides containing D-amino acid residues, which may be ...
Hoefling Martin - - 2010
Interactions of proteins with inorganic surfaces are of high importance in biological events and in modern biotechnological applications. Therefore, peptides have been engineered to recognize inorganic surfaces with high specificity. However, the underlying interactions are still not well understood. Here, we investigated the adsorption of amino acids as protein building ...
Miyamoto Tetsuya - - 2010
The number of reports indicating the occurrence of D-amino acids in various proteins and natural peptides is increasing. For a usual detection of peptidyl D-amino acids, proteins or peptides are subjected to acid hydrolysis, and the products obtained are analyzed after cancellation of the effect of amino acid racemization during ...
Basak Amit - - 2010
C(2)-Symmetric azobenzene-amino acid/peptide hybrids containing stable E-azo moiety have been synthesized. Upon irradiation with long wavelength UV, these compounds isomerized to the Z-form, whose thermal reisomerization to the E isomer slowed down considerably. These compounds exhibited in vitro moderate to strong inhibition of mammalian cellular protease Subtilisin Kexin Isozyme-1, also ...
Risseeuw Martijn D P - - 2010
This paper describes the synthesis and biological evaluation of nine epoxomicin-derived sugar amino acid containing peptide epoxyketones. The title compounds are assembled from six sugar amino acid dipeptide isosteres and are synthesized using solution-phase peptide synthesis protocols. Although neither of the compounds displays inhibitory activity towards any of the proteasome ...
Sundaram G S M - - 2010
The ability to incorporate non-canonical amino acids into proteins by genetic or chemical methods allows one to introduce novel chemical properties into a protein at a defined residue. Such a residue may then be modified using common organic transformations. In this way, the structure or function of the peptide may ...
Miyazawa T - - 2010
Dynamic kinetic resolution (DKR) was demonstrated in the carbodiimide-mediated couplings of N-benzoyl-DL-amino acids with L-amino acid esters: the yields of the D-L-peptides significantly exceeded 50% in some cases. N-Benzoyl-DL-t-leucine afforded the D-L-peptide almost exclusively (up to 96% yield) in the reaction with methyl L-prolinate, which is the most efficient DKR ...
Ilisz I - - 2010
Since most of the proteinogenic alpha-amino acids contain a chiral carbon atom, the stereoisomers of both these amino acids and the peptides in which they are to be found may possess differences in biological activity in living systems. The important analytical task of the separation of optical isomers is achieved ...
Fuchise Tomoyoshi - - 2010
Atlantic cod trypsin-catalyzed peptide synthesis has been studied by using p-amidino- and p-guanidinophenyl esters of N-(tert-butyloxycarbonyl)amino acid as acyl donor components. The reaction temperature was optimized at 0 degrees C. The method was shown to be successful as effectively for synthesizing the peptide and useful for preparing dipeptide between D-amino ...
Guidolin Diego - - 2010
Angiogenesis, the process through which new blood vessels arise from pre-existing ones, is regulated by numerous "classic" factors and other "nonclassic" regulators of angiogenesis. Among these latter urotensin-II is a cyclic 11-amino acid (human) or 15-amino acid (rodent) peptide, originally isolated from the fish urophysis, which exerts a potent systemic ...
Gothard Chris M CM Department of Chemistry University of California, Irvine, California 92697-2025, - - 2010
This paper introduces the unnatural amino acids m-Abc(2K) and o-Abc(2K) as nanometer-sized building blocks for the creation of water-soluble macrocycles with well-defined shapes. m-Abc(2K) and o-Abc(2K) are homologues of the nanometer-sized amino acid Abc(2K), which we recently introduced for the synthesis of water-soluble molecular rods of precise length (J. Am. ...
Watts R Edward RE Department of Pharmacology and Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, 2222 Pierce Avenue, Nashville, Tennessee 37232, - - 2010
Ribosomal incorporations of N-alkyl amino acids including proline are slower than incorporations of non-N-alkyl l-amino acids. The chemical reactivity hypothesis proposes that these results and the exclusion of nonproline N-alkyl amino acids from the genetic code are explained by intrinsic chemical reactivities of the amino acid nucleophiles. However, there is ...
Neumann Heinz H Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, - - 2010
The in vivo, genetically programmed incorporation of designer amino acids allows the properties of proteins to be tailored with molecular precision. The Methanococcus jannaschii tyrosyl-transfer-RNA synthetase-tRNA(CUA) (MjTyrRS-tRNA(CUA)) and the Methanosarcina barkeri pyrrolysyl-tRNA synthetase-tRNA(CUA) (MbPylRS-tRNA(CUA)) orthogonal pairs have been evolved to incorporate a range of unnatural amino acids in response to ...
Young Travis S - - 2010
The ability to genetically encode unnatural amino acids beyond the common 20 has allowed unprecedented control over the chemical structures of recombinantly expressed proteins. Orthogonal aminoacyl-tRNA synthetase/tRNA pairs have been used together with nonsense, rare, or 4-bp codons to incorporate >50 unnatural amino acids into proteins in Escherichia coli, Saccharomyces ...
Bongo Nlandu B - - 2010
Based on the application of our recent biotinyl photoprobe with a cleavable N-acylsulfonamide, an efficient process has been developed for profiling photoaffinity labeled peptides among a large excess of unlabeled concomitants. N-acylsulfonamide group was found to be stable under the usual S-pyridylethylation condition of cysteine residues whereas the group was ...
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