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A new synthetic protocol for coumarin amino acid
Xinyi Xu,Xiaosong Hu,Jiangyun Wang
Beilstein Journal of Organic Chemistry , 2013, DOI: 10.3762/bjoc.9.30
Abstract: The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-yl)ethyl)glycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.
An Expanded Set of Amino Acid Analogs for the Ribosomal Translation of Unnatural Peptides  [PDF]
Matthew C. T. Hartman, Kristopher Josephson, Chi-Wang Lin, Jack W. Szostak
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000972
Abstract: Background The application of in vitro translation to the synthesis of unnatural peptides may allow the production of extremely large libraries of highly modified peptides, which are a potential source of lead compounds in the search for new pharmaceutical agents. The specificity of the translation apparatus, however, limits the diversity of unnatural amino acids that can be incorporated into peptides by ribosomal translation. We have previously shown that over 90 unnatural amino acids can be enzymatically loaded onto tRNA. Methodology/Principal Findings We have now used a competition assay to assess the efficiency of tRNA-aminoacylation of these analogs. We have also used a series of peptide translation assays to measure the efficiency with which these analogs are incorporated into peptides. The translation apparatus tolerates most side chain derivatives, a few α,α disubstituted, N-methyl and α-hydroxy derivatives, but no β-amino acids. We show that over 50 unnatural amino acids can be incorporated into peptides by ribosomal translation. Using a set of analogs that are efficiently charged and translated we were able to prepare individual peptides containing up to 13 different unnatural amino acids. Conclusions/Significance Our results demonstrate that a diverse array of unnatural building blocks can be translationally incorporated into peptides. These building blocks provide new opportunities for in vitro selections with highly modified drug-like peptides.
D. Qujeq
Acta Medica Iranica , 1998,
Abstract: Gamma-aminobutyric acid is the main inhibitory amino acid neurotransmitter in several areas of the brain. Measurement of gamma-aminobutyric acid in the brain will help elucidate its metabolic rote and diagnostic value. The liquid chromatography (LC) system consisted of a delivery pump. Male rats (150-250g) were used in this study. The brain was rapidly removed from decapitated animals. Trie chromatograms showed satisfactory resolution and symmetrical peak shapes, both with the standard and tissue extracts. the retention lime was 4.60 min. it was constant in repeated analyses and exactly the same for the standard and tissue samples.
Comparative efficacy of supplementation of phytoconcentrate herbal preparation and synthetic amino acid on broiler performance
A. B. Kanduri,N. Z. Gaikwad,V. K. Mugale,Shivi Maini
Veterinary World , 2011,
Abstract: In view to study the role of herbal sources of essential amino acids in improving growth & performance, an experiment was conducted on seventy five day Vencob broiler chicks. Chicks were randomly divided into three groups (n=25), one negative control (T0) and two treatments (T1 & T2). Control group (T0) was offered basal diet deficient in natural or synthetic source of amino acids (choline, methionine, lysine & biotin). Treatment group T1 was fed with basal diet supplemented with polyherbal formulation comprising natural sources (herbs) that mimic the activity of amino acids (choline, methionine, lysine & biotin) @ 2Kg/tonne of feed while treatment group T2 was fed with basal diet supplemented with combination of synthetic choline chloride (600gm/tonne), synthetic methionine (1kg/tonne), synthetic lysine (1kg/tonne) and biotin (150mg/tonne). Growth & performance parameters were recorded at weekly intervals and a metabolic trial for nutrient retention studies was conducted at the end of study. A significant increase in mean body weight gain, mean final body weight, feed efficiency & nutrient retention was observed in both the treated groups as compared to untreated control. The results of group T1 supplemented with herbal sources of amino acids were in confirmation with T2 supplemented with combination of synthetic amino acids suggesting that the polyherbal formula can successfully replace synthetic additives in feed. [Vet. World 2011; 4(9.000): 413-416]
The Complete Genome Sequence of Natrinema sp. J7-2, a Haloarchaeon Capable of Growth on Synthetic Media without Amino Acid Supplements  [PDF]
Jie Feng, Bin Liu, Ziqian Zhang, Yan Ren, Yang Li, Fei Gan, Yuping Huang, Xiangdong Chen, Ping Shen, Lei Wang, Bing Tang, Xiao-Feng Tang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041621
Abstract: Natrinema sp. J7-2 is an extreme haloarchaeon capable of growing on synthetic media without amino acid supplements. Here we report the complete genome sequence of Natrinema sp. J7-2 which is composed of a 3,697,626-bp chromosome and a 95,989-bp plasmid pJ7-I. This is the first complete genome sequence of a member of the genus Natrinema. We demonstrate that Natrinema sp. J7-2 can use gluconate, glycerol, or acetate as the sole carbon source and that its genome encodes complete metabolic pathways for assimilating these substrates. The biosynthetic pathways for all 20 amino acids have been reconstructed, and we discuss a possible evolutionary relationship between the haloarchaeal arginine synthetic pathway and the bacterial lysine synthetic pathway. The genome harbors the genes for assimilation of ammonium and nitrite, but not nitrate, and has a denitrification pathway to reduce nitrite to N2O. Comparative genomic analysis suggests that most sequenced haloarchaea employ the TrkAH system, rather than the Kdp system, to actively uptake potassium. The genomic analysis also reveals that one of the three CRISPR loci in the Natrinema sp. J7-2 chromosome is located in an integrative genetic element and is probably propagated via horizontal gene transfer (HGT). Finally, our phylogenetic analysis of haloarchaeal genomes provides clues about evolutionary relationships of haloarchaea.
Cultivation of Arthrospira (spirulina) platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile
Volkmann, Harriet;Imianovsky, Ulisses;Oliveira, Jorge L.B.;Sant'Anna, Ernani S.;
Brazilian Journal of Microbiology , 2008, DOI: 10.1590/S1517-83822008000100022
Abstract: arthrospira (spirulina) platensis was cultivated in laboratory under controlled conditions (30oc, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 μmol photons.m-2.s-1 and constant bubbling air) in three different culture media: (1) paoletti medium (control), (2) paoletti supplemented with 1 g.l-1 nacl (salinated water) and (3) paoletti medium prepared with desalinator wastewater. the effects of these treatments on growth, protein content and amino acid profile were measured. maximum cell concentrations observed in paoletti medium, paoletti supplemented with salinated water or with desalinator wastewater were 2.587, 3.545 and 4.954 g.l-1, respectively. biomass in medium 3 presented the highest protein content (56.17%), while biomass in medium 2 presented 48.59% protein. all essential amino acids, except lysine and tryptophan, were found in concentrations higher than those requiried by fao.
Function and evolution of the serotonin-synthetic bas-1 gene and other aromatic amino acid decarboxylase genes in Caenorhabditis
Emily E Hare, Curtis M Loer
BMC Evolutionary Biology , 2004, DOI: 10.1186/1471-2148-4-24
Abstract: In the nematode C. elegans, the bas-1 gene is required for both serotonin and dopamine synthesis, and maps genetically near two AADC-homologous sequences. We show by transformation rescue and sequencing of mutant alleles that bas-1 encodes an AADC enzyme. Expression of a reporter construct in transgenics suggests that the bas-1 gene is expressed, as expected, in identified serotonergic and dopaminergic neurons. The bas-1 gene is one of six AADC-like sequences in the C. elegans genome, including a duplicate that is immediately downstream of the bas-1 gene. Some of the six AADC genes are quite similar to known serotonin- and dopamine-synthetic AADC's from other organisms whereas others are divergent, suggesting previously unidentified functions. In comparing the AADC genes of C. elegans with those of the congeneric C. briggsae, we find only four orthologous AADC genes in C. briggsae. Two C. elegans AADC genes – those most similar to bas-1 – are missing from C. briggsae. Phylogenetic analysis indicates that one or both of these bas-1-like genes were present in the common ancestor of C. elegans and C. briggsae, and were retained in the C. elegans line, but lost in the C. briggsae line. Further analysis of the two bas-1-like genes in C. elegans suggests that they are unlikely to encode functional enzymes, and may be expressed pseudogenes.The bas-1 gene of C. elegans encodes a serotonin- and dopamine-synthetic AADC enzyme. Two C. elegans AADC-homologous genes that are closely related to bas-1 are missing from the congeneric C. briggsae; one or more these genes was present in the common ancestor of C. elegans and C. briggsae. Despite their persistence in C. elegans, evidence suggests the bas-1-like genes do not encode functional AADC proteins. The presence of the genes in C. elegans raises questions about how many 'predicted genes' in sequenced genomes are functional, and how duplicate genes are retained or lost during evolution. This is another example of unexpected reten
Production of gamma-aminobutyric acid by Lactobacillus brevis NCL912 using fed-batch fermentation
Haixing Li, Ting Qiu, Guidong Huang, Yusheng Cao
Microbial Cell Factories , 2010, DOI: 10.1186/1475-2859-9-85
Abstract: Pyridoxal-5'-phosphate did not affect the cell growth and gamma-aminobutyric acid production of Lb. brevis NCL912. Temperature, pH and initial glutamate concentration had significant effects on the cell growth and gamma-aminobutyric acid production of Lb. brevis NCL912. The optimal temperature, pH and initial glutamate concentration were 30-35°C, 5.0 and 250-500 mM. In the following fed-batch fermentations, temperature, pH and initial glutamate concentration were fixed as 32°C, 5.0 and 400 mM. 280.70 g (1.5 mol) and 224.56 g (1.2 mol) glutamate were supplemented into the bioreactor at 12 h and 24 h, respectively. Under the selected fermentation conditions, gamma-aminobutyric acid was rapidly produced at the first 36 h and almost not produced after then. The gamma-aminobutyric acid concentration reached 1005.81 ± 47.88 mM, and the residual glucose and glutamate were 15.28 ± 0.51 g L-1 and 134.45 ± 24.22 mM at 48 h.A simple and effective fed-batch fermentation method was developed for Lb. brevis NCL912 to produce gamma-aminobutyric acid. The results reveal that Lb. brevis NCL912 exhibits a great application potential in large-scale fermentation for the production of gamma-aminobutyric acid.Gamma-aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in nature from microorganisms to plants and animals [1]. It acts as the major inhibitory neurotransmitter in the mammalian central nervous system. In addition, GABA has hypotensive, tranquilizing and diuretic effects, and can prevent diabetes [2-5]. Also, GABA may improve the concentration of plasma growth hormone and the rate of protein synthesis in the brain [6] and inhibit small airway-derived lung adenocarcinoma [7]. Therefore, GABA has potential as a bioactive component in foods and pharmaceuticals [8]. However, the direction addition of chemical GABA to food is considered unnatural and unsafe [8-10]. So it is necessary to find a natural method to produce and increase GABA in food.Recent studi
Saturated Alanine Scanning Mutagenesis of the Pneumococcus Competence Stimulating Peptide Identifies Analogs That Inhibit Genetic Transformation  [PDF]
Chaohui Duan, Luchang Zhu, Ying Xu, Gee W. Lau
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044710
Abstract: Antibiotic resistance is a major challenge to modern medicine. Intraspecies and interspecies dissemination of antibiotic resistance genes among bacteria can occur through horizontal gene transfer. Competence-mediated gene transfer has been reported to contribute to the spread of antibiotic resistance genes in Streptococcus pneumoniae. Induction of the competence regulon is mediated by a 17-amino acid peptide pheromone called the competence stimulating peptide (CSP). Thus, synthetic analogs that competitively inhibit CSPs may reduce horizontal gene transfer. We performed saturated alanine scanning mutagenesis and other amino acid substitutions on CSP1 to screen for analogs that disable genetic transformation in S. pneumoniae. Substitution of the glutamate residue at the first position created analogs that could competitively inhibit CSP1-mediated competence development in a concentration-dependent manner. Additional substitutions of the negatively-charged glutamate residue with amino acids of different charge, acidity and hydrophobicity, as well as enantiomeric D-glutamate, generated analogs that efficiently outcompeted CSP1, suggesting the importance of negative charge and enantiomericity of the first glutamate residue for the function of CSP1. Collectively, these results indicate that glutamate residue at the first position is important for the ability of CSP1 to induce ComD, but is dispensable for the peptide to bind the receptor. Furthermore, these results demonstrate the potential applicability of competitive CSP analogs to control horizontal transfer of antibiotic resistance genes in S. pneumoniae.
The role of γ -aminobutyric acid (Gaba) in somatic embryogenesis of Acca sellowiana Berg. (Myrtaceae)
Booz, Maristela Raitz;Kerbauy, Gilberto B.;Guerra, Miguel Pedro;Pescador, Rosete;
Brazilian Journal of Plant Physiology , 2009, DOI: 10.1590/S1677-04202009000400003
Abstract: the γ-aminobutyric acid (gaba) is a non-protein amino acid found in prokaryotes and eukaryotes. its role in plant development has not been fully established. this study reports a quantification of the levels of endogenous gaba, as well as investigation of its role in different stages of somatic embryogenesis in acca sellowiana berg. (myrtaceae). zygotic embryos were used as explants and they were inoculated into the culture medium contained different concentrations of gaba (0,2, 4, 6, 8 and 10 μm). the highest concentrations of endogenous gaba were detected between the third and nine days after inoculation, reaching the value of 12.77 μmol.g-1fw. high frequency of somatic embryogenesis was observed in response to 10 μm gaba. this treatment also resulted in a large number of normal embryos, and the lowest percentage of formation of fused somatic embryos, phenotypic characteristic of most deformed embryos in all treatments. also, all treatments promoted the formation of the somatic embryos with positive characteristics of development resumption, which however did not originate the seedlings.
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