scholarly journals N-Heterocyclic Carbene-Catalyzed Random Copolymerization of N-Carboxyanhydrides of α-Amino Acids

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3674
Author(s):  
Kuen Hee Eom ◽  
Seokhyeon Baek ◽  
Il Kim
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Primary Structure ◽  
Reactivity Ratio ◽  
Synthetic Polypeptides ◽  
Random Placement ◽  
Natural Peptides ◽  
The Relationship ◽  
Method Show

Synthetic polypeptides prepared from N-carboxyanhydrides (NCAs) of α-amino acids are useful for elucidating the relationship between the primary structure of natural peptides and their immunogenicity. In this study, complex copolypeptide sequences were prepared using a recently developed technique; specifically, the random copolymerization of l-alanine NCA with NCAs of l-glutamic acid 5-benzylester (Bn-Glu NCA), S-benzyl-cysteine (Bn-Cys NCA), O-benzyl-l-serine (Bn-Ser NCA), and l-phenylalanine (Phe NCA) was performed using N-heterocyclic carbene (NHC) catalysts. The NHC-initiated Ala NCA/Bn-Glu NCA and Ala NCA/Bn-Cys NCA copolymerization reactions achieved 90% conversion within 30 min. The reactivity ratio values estimated using the Kelen and Tüdos method show that poly(Bn-Glu-co-Ala) and poly(Bn-Cys-co-Ala) have random repeating units with rich alternating sequences, whereas poly(Bn-Ser-co-Ala) and poly(Phe-co-Ala) contain a larger proportion of Ala-repeating units than Bn-Ser and Phe in random placement.

scholarly journals The Amino Acid Contents in Mangrove Rhizophora mucronata Leaves in Asahan, North Sumatra, Indonesia

2020 ◽  
Vol 151 ◽  
pp. 01047
Author(s):  
Sri S. Ningsih ◽  
Dafit Ariyanto ◽  
Dian Puspitasari ◽  
Anuraga Jayanegara ◽  
Hamim Hamim ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Amino Acid Content ◽  
Principal Component ◽  
Mangrove Plant ◽  
Relationship Analysis ◽  
The Difference ◽  
Amino Acid Contents ◽  
The Relationship

Amino acids are important components of mangrove plant metabolisms. The aim of this study was to determine the relationship of mangrove R. mucronata leaf colors to the amino acid content. This study was conducted between March to August 2019. The leaves were taken 50 g. The assessment of Amino acids was conducted using UPLC Waters Acquity Class H with PDA Detector. The principal component analysis (PCA) was used to determine the relationship analysis between R. mucronata leaf colors and amino acid concentrations. The largest content was L glutamic acid with a green leaf content of 6139.57 ± 694.17 mg/kg and yellow leaf content of 6105.013 ± 113.2058 mg/kg. The results of PCA 1 showed that the influential amino acids were L-threonine (0.94), L-tyrosine (0.96), L-alanine (0.92), L-vanin (0.93), and PCA 2 showed glutamic acid (0.91). These results indicated that the difference in mangrove leaf colors affects the amino acid contents in the leaves.

The Proteins of Hevea Brasiliensis. 1. Analysis of a Product Isolated from Dried Latex

1940 ◽  
Vol 13 (4) ◽  
pp. 722-727
Author(s):  
G. R. Tristram
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Total Protein ◽  
Hevea Brasiliensis ◽  
Dicarboxylic Acids ◽  
Calcium Salts ◽  
Basic Amino Acids ◽  
Relationship Of ◽  
The Relationship

Abstract A protein has been isolated from dried Hevea latex and analyzed for amido-nitrogen, tyrosine, tryptophan, cystine, methionine, the basic amino-acids and the dicarboxylic acids. The dicarboxylic acids were estimated in 4.0 grams of protein, experiments on casein having shown that, under such conditions, approximately 90% of the glutamic acid and aspartic acid was recovered as crystalline derivatives. It was also found possible to estimate arginine and lysine in the filtrate from the calcium salts of the dicarboxylic acids. The protein is, in many respects, similar to the proteins found in leaves of other plants (Table IV). Further work is in progress to investigate the relationship of the isolated protein to the total protein of latex.

Isoleucine Plays an Important Role for Maintaining Immune Function

2019 ◽  
Vol 20 (7) ◽  
pp. 644-651 ◽  
Author(s):  
Changsong Gu ◽  
Xiangbing Mao ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Qing Yang
Keyword(s):  
Amino Acids ◽  
Acid Metabolism ◽  
Branched Chain Amino Acids ◽  
Whole Body ◽  
Immune Functions ◽  
Host Defense Peptides ◽  
Innate And Adaptive Immunity ◽  
Physiological Functions ◽  
Branched Chain ◽  
The Relationship

Branched chain amino acids are the essential nutrients for humans and many animals. As functional amino acids, they play important roles in physiological functions, including immune functions. Isoleucine, as one of the branched chain amino acids, is also critical in physiological functions of the whole body, such as growth, immunity, protein metabolism, fatty acid metabolism and glucose transportation. Isoleucine can improve the immune system, including immune organs, cells and reactive substances. Recent studies have also shown that isoleucine may induce the expression of host defense peptides (i.e., β-defensins) that can regulate host innate and adaptive immunity. In addition, isoleucine administration can restore the effect of some pathogens on the health of humans and animals via increasing the expression of β-defensins. Therefore, the present review will emphatically discuss the effect of isoleucine on immunity while summarizing the relationship between branched chain amino acids and immune functions.

ChemInform Abstract: Enantiocontrolled Synthesis of Two Amino Acids. (S)-Glutamic Acid and ( S)-2-Aminoadipic Acid.

ChemInform ◽  
2010 ◽  
Vol 25 (40) ◽  
pp. no-no
Author(s):  
S. TAKANO ◽  
T. KAMIKUBO ◽  
M. MORIYA ◽  
K. OGASAWARA
Keyword(s):  
Amino Acids ◽  
Glutamic Acid

scholarly journals Unfolding of Helical Poly(L-Glutamic Acid) in N,N-Dimethylformamide Probed by Pyrene Excimer Fluorescence (PEF)

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1690
Author(s):  
Weize Yuan ◽  
Remi Casier ◽  
Jean Duhamel
Keyword(s):  
Glutamic Acid ◽  
Local Density ◽  
Guanidine Hydrochloride ◽  
Racemic Mixture ◽  
Excimer Fluorescence ◽  
Excimer Formation ◽  
Blob Model ◽  
Α Helix ◽  
The Relationship ◽  
Pyrene Excimer Formation

The denaturation undergone by α–helical poly(L-glutamic acid) (PLGA) in N,N-dimethylformamide upon addition of guanidine hydrochloride (GdHCl) was characterized by comparing the fluorescence of a series of PLGA constructs randomly labeled with the dye pyrene (Py-PLGA) to that of a series of Py-PDLGA samples prepared from a racemic mixture of D,L-glutamic acid. The process of pyrene excimer formation (PEF) was taken advantage of to probe changes in the conformation of α–helical Py-PLGA. Fluorescence Blob Model (FBM) analysis of the fluorescence decays of the Py-PLGA and Py-PDLGA constructs yielded the average number (<Nblob>) of glutamic acids located inside a blob, which represented the volume probed by an excited pyrenyl label. <Nblob> remained constant for randomly coiled Py-PDLGA but decreased from ~20 to ~10 glutamic acids for the Py-PLGA samples as GdHCl was added to the solution. The decrease in <Nblob> reflected the decrease in the local density of PLGA as the α–helix unraveled in solution. The changes in <Nblob> with GdHCl concentration was used to determine the change in Gibbs energy required to denature the PLGA α–helix in DMF. The relationship between <Nblob> and the local density of macromolecules can now be applied to characterize the conformation of macromolecules in solution.

EFFECTS OF HYPOGLYCIN A ON THE METABOLISM OF AMINO ACIDS BY LIVER SLICES

1964 ◽  
Vol 42 (1) ◽  
pp. 139-142 ◽  
Author(s):  
S. J. Patrick ◽  
L. C. Stewart
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Inhibitory Effects ◽  
Liver Slices

The effects of hypoglycin A on the metabolism of L-leucine-C14, L-alanine-C14, and L-glutamic-acid-C14 by rat liver slices have been investigated. Hypoglycin exerted markedly inhibitory effects on the conversion of leucine-C14 to fatty acid, cholesterol, and CO2. Conversion of alanine-C14 and glutamic acid-C14 to fatty acids was also inhibited by hypoglycin. No effects of hypoglycin on the conversion of C14-amino acids into protein or glycogen were demonstrated.

Study of the relationship between free amino acids and cataract in human lenses

1984 ◽  
Vol 38 (2) ◽  
pp. 177-179 ◽  
Author(s):  
B.S. Chauhan ◽  
N.C. Desai ◽  
Ramesh Bhatnagar ◽  
S.P. Garg
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Human Lenses ◽  
The Relationship
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