scholarly journals A reliable LC-MS/MS method for the quantification of natural amino acids in mouse plasma: Method validation and application to a study on amino acid dynamics during hepatocellular carcinoma progression

2019 ◽  
Vol 1124 ◽  
pp. 72-81 ◽  
Author(s):  
Zhenzhen Liu ◽  
Mei-Juan Tu ◽  
Chao Zhang ◽  
Joseph L. Jilek ◽  
Qian-Yu Zhang ◽  
...  
RSC Advances ◽  
2015 ◽  
Vol 5 (95) ◽  
pp. 77538-77544 ◽  
Author(s):  
Arukali Sammaiah ◽  
Korlipara V. Padmaja ◽  
Shiva Shanker Kaki ◽  
Rachapudi B. N. Prasad

Novel multifunctional additives were synthesized from methyl oleate via thioglycolic acid addition followed by condensation with different amino acid methyl esters.


2013 ◽  
Vol 22 (6) ◽  
pp. 1567-1571 ◽  
Author(s):  
You-Shin Shim ◽  
Won-Jin Yoon ◽  
Jaeho Ha ◽  
Dongwon Seo ◽  
Kwang-Won Lee ◽  
...  

2012 ◽  
Vol 1 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Hong-Ying Niu ◽  
Shi-Xia Bai ◽  
Shan Wu ◽  
Gui-Rong Qu ◽  
Hai-Ming Guo

2019 ◽  
Vol 400 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Tobias Krüger ◽  
Thomas Dierks ◽  
Norbert Sewald

Abstract Site-specific bioconjugation strategies offer many possibilities for directed protein modifications. Among the various enzyme-based conjugation protocols, formylglycine-generating enzymes allow to posttranslationally introduce the amino acid Cα-formylglycine (FGly) into recombinant proteins, starting from cysteine or serine residues within distinct consensus motifs. The aldehyde-bearing FGly-residue displays orthogonal reactivity to all other natural amino acids and can, therefore, be used for site-specific labeling reactions on protein scaffolds. In this review, the state of research on catalytic mechanisms and consensus motifs of different formylglycine-generating enzymes, as well as labeling strategies and applications of FGly-based bioconjugations are presented.


2020 ◽  
Vol 3 (1) ◽  
pp. 471-482 ◽  
Author(s):  
Stacey Bartlett ◽  
Mariusz Skwarczynski ◽  
Xin Xie ◽  
Istvan Toth ◽  
Alex Loukas ◽  
...  

Peptide-based vaccines consist of short antigen fragments derived from a specific pathogen. Alone, these peptide fragments are poorly or non-immunogenic; however, when incorporated into a proper delivery system, they can trigger strong immune responses. To eliminate the need for toxic and often ineffective oral adjuvants, we designed single molecule-based self-adjuvating vaccines against hookworms using natural and unnatural hydrophobic amino acids. Two vaccine conjugates were synthesized, consisting of B-cell epitope p3, derived from the hookworm Na-APR-1 protein; universal T-helper peptide P25; and either double copies of unnatural lipoamino acid (2-amino-D,L-eicosanoic acid), or ten copies of the natural amino acid leucine. After challenge with the model hookworm, Nippostrongylus brasiliensis, mice orally immunized with the conjugates, but without adjuvant, generated antibody responses against the hookworm epitope, resulting in significantly reduced worm and egg burdens compared to control mice. We have demonstrated that vaccine nanoparticles composed exclusively of natural amino acids can be effective even when administered orally.


2020 ◽  
Vol 1 (6) ◽  
pp. 1980-1987
Author(s):  
Praveen Singh Gehlot ◽  
Hariom Gupta ◽  
Mangal Singh Rathore ◽  
Kusum Khatri ◽  
Arvind Kumar

Paramagnetic ionic liquids (PMILs) comprising of natural amino acids and tetrachloroferrate(iii) as constituent ions were prepared that act as highly efficient dual mode (T1 and T2) responsive contrast agents for magnetic resonance imaging (MRI).


2013 ◽  
Vol 69 (12) ◽  
pp. o1829-o1830 ◽  
Author(s):  
Ray J. Butcher ◽  
Greg Brewer ◽  
Aaron S. Burton ◽  
Jason P. Dworkin

The title compound, C5H11NO2·H2O, is an isomer of the α-amino acid valine that crystallizes from water in its zwitterion form as a monohydrate. It is not one of the 20 proteinogenic amino acids that are used in living systems and differs from the natural amino acids in that it has no α-H atom. The compound exhibits hydrogen bonding between the water molecule and the carboxylate O atoms and an amine H atom. In addition, there are intermolecular hydrogen-bonding interactions between the carboxylate O atoms and amine H atoms. In the crystal, these extensive N—H...O and O—H...O hydrogen bonds lead to the formation of a three-dimensional network.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 242
Author(s):  
Yuuki Yamawaki ◽  
Tomoki Yufu ◽  
Tamaki Kato

7-Amino-4-methylcoumarin (AMC) is a low molecular weight fluorescent probe that can be attached to a peptide to enable the detection of specific proteases, such as chymotrypsin, expressed in certain diseases. Because this detection depends on the specificity of the protease toward the peptidyl AMC, the development of specific substrates is required. To investigate the specificity of chymotrypsin, peptidyl AMC compounds incorporating four different amino acid residues were prepared by liquid-phase synthesis. Two unnatural amino acids, 2-amino-4-ethylhexanoic acid (AEH) and cyclohexylalanine (Cha), were used to investigate the substrate specificity as these amino acids have structures different from natural amino acids. AEH was synthesized using diethyl acetamidemalonate as a starting material. The substrate containing Cha had high hydrophobicity and showed a high reaction velocity with chymotrypsin. Although the AEH substrate with a branched side chain had high hydrophobicity, it showed a low reaction velocity. The substrate containing the aromatic amino acid phenylalanine was less hydrophobic than the Cha and AEH substrates, but chymotrypsin showed the highest specificity for this compound. These results demonstrated that the substrate specificity of chymotrypsin is not only affected by the hydrophobicity and aromaticity, but also by the structural expanse of amino acid residues in the substrate.


1960 ◽  
Vol 38 (4) ◽  
pp. 467-476 ◽  
Author(s):  
D. J. Samborski ◽  
F. R. Forsyth

The effect of metabolites and antimetabolites on rust development was studied, using detached leaves of Little Club wheat floated on solutions containing benzimidazole plus the compound under study. Purines and pyrimidines, vitamins, amino acids, carbohydrates, and enzyme poisons were tested. A number of these compounds inhibited leaf and stem rusts of wheat at concentrations that were not injurious to the host. Of the purines and pyrimidines that were tested, thymine and the analogue azathymine were the only effective inhibitors. The antivitamin oxythiamine was inhibitory and the inhibition was competitively reversed by thiamine.A few natural amino acids, notably histidine, isoleucine, methionine, and serine, inhibited rust development. The inhibition was reversed by glycine in all cases except with serine. Amino acid analogues, particularly canavanine, ethionine, and p-fluorophenylalanine, were excellent inhibitors; the inhibitions were reversed by comparable levels of arginine, methionine, and phenylalanine respectively. The carbohydrates lyxose, xylose, sorbose, and all the sugar alcohols tested were effective inhibitors of rust development. Of the enzyme poisons tested, sodium fluoride and sodium azide differentially inhibited rust growth.


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