scholarly journals Mycosporine-Like Amino Acids from Coral Dinoflagellates

2011 ◽  
Vol 77 (24) ◽  
pp. 8478-8486 ◽  
Author(s):  
Nedeljka N. Rosic ◽  
Sophie Dove
Keyword(s):  
Amino Acids ◽  
Current Knowledge ◽  
Shikimate Pathway ◽  
Pentose Phosphate ◽  
Marine Organisms ◽  
Water Soluble ◽  
Coral Tissue ◽  
Biological Macromolecules ◽  
Abiotic Factor ◽  
Coral Host

ABSTRACTCoral reefs are one of the most important marine ecosystems, providing habitat for approximately a quarter of all marine organisms. Within the foundation of this ecosystem, reef-building corals form mutualistic symbioses with unicellular photosynthetic dinoflagellates of the genusSymbiodinium. Exposure to UV radiation (UVR) (280 to 400 nm) especially when combined with thermal stress has been recognized as an important abiotic factor leading to the loss of algal symbionts from coral tissue and/or a reduction in their pigment concentration and coral bleaching. UVR may damage biological macromolecules, increase the level of mutagenesis in cells, and destabilize the symbiosis between the coral host and their dinoflagellate symbionts. In nature, corals and other marine organisms are protected from harmful UVR through several important photoprotective mechanisms that include the synthesis of UV-absorbing compounds such as mycosporine-like amino acids (MAAs). MAAs are small (<400-Da), colorless, water-soluble compounds made of a cyclohexenone or cyclohexenimine chromophore that is bound to an amino acid residue or its imino alcohol. These secondary metabolites are natural biological sunscreens characterized by a maximum absorbance in the UVA and UVB ranges of 310 to 362 nm. In addition to their photoprotective role, MAAs act as antioxidants scavenging reactive oxygen species (ROS) and suppressing singlet oxygen-induced damage. It has been proposed that MAAs are synthesized during the first part of the shikimate pathway, and recently, it has been suggested that they are synthesized in the pentose phosphate pathway. The shikimate pathway is not found in animals, but in plants and microbes, it connects the metabolism of carbohydrates to the biosynthesis of aromatic compounds. However, both the complete enzymatic pathway of MAA synthesis and the extent of their regulation by environmental conditions are not known. This minireview discusses the current knowledge of MAA synthesis, illustrates the diversity of MAA functions, and opens new perspectives for future applications of MAAs in biotechnology.

scholarly journals Relation between vitamins of the b complex, GABA and glutamate, and their role in neurocognitive disorders -Brief review

2016 ◽  
Vol 5 (4) ◽  
pp. 229 ◽  
Author(s):  
Rayssa Justo ◽  
Marcelo Cesar ◽  
Edimilson Migowski ◽  
Rafael Cisne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Behavioral Control ◽  
The Elderly ◽  
Cognitive Disorder ◽  
Pentose Phosphate ◽  
Water Soluble ◽  
Excitatory Neurotransmitters ◽  
Brain And Behavior ◽  
And Behavior

Vitamins, especially the water-soluble complex of vitamins B, are highlighted in the daily clinical practice. Numerous studies emphasize the need for supplementation, mainly in groups with deficiency of these vitamins, such as the elderly, pregnant women, children and patients with diseases associates with cognitive disorder. Thiamine (B1), a vitamin of the diet, is an important cofactor for the three key enzymes involved in the citric acid cycle and the pentose phosphate cycle. Pyridoxine (B6) and cobalamin (B12) act in the CNS as a cofactor in the metabolism reactions of homocysteine. Deficiency of some neurotransmitter precursors can also cause symptoms of attention deficit hyperactivity disorder in children, especially amino acid and vitamin B deficiency. Inhibitory and excitatory neurotransmitters regulate diverse behavioral processes, including sleep, learning, memory and sensation of pain. They are also implicated in many pathological processes, such as epilepsy and neurotoxicity. Studies suggest that the excitatory amino acids may play a role in learning and memory. The binding of glutamate to its receptor triggers molecular and cellular events associated with numerous physiological and pathophysiological pathways, including the development of an increased sensation of pain (hyperalgesia), brain neurotoxicity or synaptic alterations involved in certain types of memory formation. Between the two major classes of neuroactive amino acids, γ-aminobutyric acid (GABA) is the major inhibitory amino acid. It is known that GABA plays a fundamental role in encoding information and behavioral control, in the regulation of motor function and in motor learning. The inter-relationships between diet, the brain and behavior are complex. However, micronutrients are known to have a direct influence on cognitive function through their involvement in the energy metabolism of neurons and glia cells, the synthesis of neurotransmitters, receptor binding and the maintenance of membrane ion pumps.

The Shikimate Pathway: Biosynthesis of Phenolic Products from Shikimic Acid

2016 ◽  
Author(s):  
Gary W. Morrow
Keyword(s):  
Amino Acids ◽  
Secondary Metabolites ◽  
Shikimic Acid ◽  
Shikimate Pathway ◽  
Aromatic Amino Acids ◽  
Essential Amino Acids ◽  
Bimolecular Reaction ◽  
Pentose Phosphate ◽  
Chemotherapy Agent ◽  
Acid Pathway

Like other amino acids, the aromatic amino acids phenylalanine, tyrosine, and tryptophan are vitally important for protein synthesis in all organisms. However, while animals can synthesize tyrosine via oxidation of phenylalanine, they can synthesize neither phenylalanine itself nor tryptophan and so these essential amino acids must be obtained in the diet, usually from plant material. Though many other investigators made significant contributions in this area over the years, it was Bernhard Davis in the early 1950s whose use of mutant stains of Escherichia coli led to a full understanding of the so-called shikimic acid pathway that is used by plants and also by some microorganisms for the biosynthesis of these essential amino acids. The pathway is almost completely devoted to their synthesis for protein production in bacteria, while in plants the pathway extends their use to the construction of a wide array of secondary metabolites, many of which are valuable medicinal agents. These secondary metabolites range from simple and familiar compounds such as vanillin (vanilla flavor and fragrance) and eugenol (oil of clove, a useful dental anesthetic) to more complex structures such as pinoresinol, a common plant biochemical, and podophyllotoxin, a powerful cancer chemotherapy agent. Earlier in Chapter 3, we encountered two important intermediates, erythrose-4-phosphate and phosphoenolpyruvate (PEP), each of which was derived from a different pathway utilized in carbohydrate metabolism. Erythrose-4-P was an intermediate in one of the steps of the pentose phosphate pathway while hydrolysis of PEP to pyruvic acid was the final step in glycolysis. These two simple intermediates provide the seven carbon atoms required for construction of shikimic acid itself. The two are linked to one another via a sequence of enzyme-mediated aldol-type reactions, the first being a bimolecular reaction and the second an intramolecular variant that ultimately leads to a cyclic precursor of shikimic acid known as 3-dehydroquinic acid as shown in Fig. 6.3. Subsequent dehydration of 3-dehydroquinic acid leads to 3-dehydroshikimic acid which then leads directly to shikimic acid via NADPH reduction.

scholarly journals Methods of plant root exudates analysis: a review

2011 ◽  
Vol 59 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Peter Dundek ◽  
Ladislav Holík ◽  
Tomáš Rohlík ◽  
Ladislav Hromádko ◽  
Valerie Vranová ◽  
...  
Keyword(s):  
Amino Acids ◽  
Organic Acids ◽  
Root Exudates ◽  
Organic Molecules ◽  
Current Knowledge ◽  
Plant Root ◽  
Water Soluble ◽  
Low Molecular Weight ◽  
Total Carbohydrates ◽  
Electrophoresis Of Proteins

The aim of this review is to summarise current knowledge on methods being used to determine individual compounds and properties of water-soluble plant root exudates. These compounds include amino acids, organic acids and simple sugars, as well as polysaccharides, proteins and organic substances. Qualitative composition of water-soluble root exudates and exudation rate are commonly measured with the aim of consequent synthetic preparation of plant root exudates to be supplied to soil to create artificial rhizosphere for different experimental purposes. Root exudates collection usually requires consequent filtration or centrifugation to remove solids, root detritus and microbial cell debris, and consequent concentration using an evaporator, lyophilizator or ultrafiltration. Methods used for analysis of total groups of compounds (total proteins and total carbohydrates) and total organic carbon are simple. On the other hand, HPLC or GS/MS are commonly used to analyse individual low molecular weight organic molecules (sugars, organic acids and amino acids) with separation using different columns. Other properties such as pH, conductivity or activity of different enzymes as well as gel electrophoresis of proteins are sometimes assessed. All of these methods are discussed in this work.

Epigenetic Mechanisms of Maternal Dietary Protein and Amino Acids Affecting Growth and Development of Offspring

2019 ◽  
Vol 20 (7) ◽  
pp. 727-735 ◽  
Author(s):  
Yi Wu ◽  
Zhibin Cheng ◽  
Yueyu Bai ◽  
Xi Ma
Keyword(s):  
Amino Acids ◽  
Dna Methylation ◽  
Dietary Protein ◽  
Growth And Development ◽  
Later Life ◽  
Biological Macromolecules ◽  
Epigenetic Mechanisms ◽  
Maternal Circulation ◽  
Energy Processing ◽  
Living Organisms

Nutrients can regulate metabolic activities of living organisms through epigenetic mechanisms, including DNA methylation, histone modification, and RNA regulation. Since the nutrients required for early embryos and postpartum lactation are derived in whole or in part from maternal and lactating nutrition, the maternal nutritional level affects the growth and development of fetus and creates a profound relationship between disease development and early environmental exposure in the offspring’s later life. Protein is one of the most important biological macromolecules, involved in almost every process of life, such as information transmission, energy processing and material metabolism. Maternal protein intake levels may affect the integrity of the fetal genome and alter DNA methylation and gene expression. Most amino acids are supplied to the fetus from the maternal circulation through active transport of placenta. Some amino acids, such as methionine, as dietary methyl donor, play an important role in DNA methylation and body’s one-carbon metabolism. The purpose of this review is to describe effects of maternal dietary protein and amino acid intake on fetal and neonatal growth and development through epigenetic mechanisms, with examples in humans and animals.

scholarly journals Malonyl-proteome profiles of Staphylococcus aureus reveal lysine malonylation modification in enzymes involved in energy metabolism

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanan Shi ◽  
Jingjing Zhu ◽  
Yan Xu ◽  
Xiaozhao Tang ◽  
Zushun Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Energy Metabolism ◽  
Active Sites ◽  
Current Knowledge ◽  
Tricarboxylic Acid Cycle ◽  
Protein A ◽  
Pentose Phosphate ◽  
Post Translational Modification ◽  
Bacterial Physiology ◽  
Dihydrolipoyl Dehydrogenase

Abstract Background Protein lysine malonylation, a novel post-translational modification (PTM), has been recently linked with energy metabolism in bacteria. Staphylococcus aureus is the third most important foodborne pathogen worldwide. Nonetheless, substrates and biological roles of malonylation are still poorly understood in this pathogen. Results Using anti-malonyl-lysine antibody enrichment and high-resolution LC-MS/MS analysis, 440 lysine-malonylated sites were identified in 281 proteins of S. aureus strain. The frequency of valine in position − 1 and alanine at + 2 and + 4 positions was high. KEGG pathway analysis showed that six categories were highly enriched, including ribosome, glycolysis/gluconeogenesis, pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA), valine, leucine, isoleucine degradation, and aminoacyl-tRNA biosynthesis. In total, 31 malonylated sites in S. aureus shared homology with lysine-malonylated sites previously identified in E. coli, indicating malonylated proteins are highly conserved among bacteria. Key rate-limiting enzymes in central carbon metabolic pathways were also found to be malonylated in S. aureus, namely pyruvate kinase (PYK), 6-phosphofructokinase, phosphoglycerate kinase, dihydrolipoyl dehydrogenase, and F1F0-ATP synthase. Notably, malonylation sites were found at or near protein active sites, including KH domain protein, thioredoxin, alanine dehydrogenase (ALD), dihydrolipoyl dehydrogenase (LpdA), pyruvate oxidase CidC, and catabolite control protein A (CcpA), thus suggesting that lysine malonylation may affect the activity of such enzymes. Conclusions Data presented herein expand the current knowledge on lysine malonylation in prokaryotes and indicate the potential roles of protein malonylation in bacterial physiology and metabolism.

Interactions of water-soluble zinc porphyrin with amino acids

1988 ◽  
Vol 153 (4) ◽  
pp. 199-200 ◽  
Author(s):  
E. Mikros ◽  
A. Gaudemer ◽  
R. Pasternack
Keyword(s):  
Amino Acids ◽  
Water Soluble ◽  
Zinc Porphyrin ◽  
Soluble Zinc

scholarly journals Incorporation of alternative amino acids into cyanophycin by different cyanophycin synthetases heterologously expressed in Corynebacterium glutamicum

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramona Wördemann ◽  
Lars Wiefel ◽  
Volker F. Wendisch ◽  
Alexander Steinbüchel
Keyword(s):  
Amino Acids ◽  
Dry Weight ◽  
Growth Conditions ◽  
Amino Acid Biosynthesis ◽  
Water Soluble ◽  
Lysine Content ◽  
Polyaspartic Acid ◽  
Acid Biosynthesis ◽  
Cyanophycin Synthetase ◽  
Potential Precursor

AbstractCyanophycin (multi-l-arginyl-poly-l-aspartic acid; also known as cyanophycin grana peptide [CGP]) is a biopolymer that could be used in various fields, for example, as a potential precursor for the synthesis of polyaspartic acid or for the production of CGP-derived dipeptides. To extend the applications of this polymer, it is therefore of interest to synthesize CGP with different compositions. A recent re-evaluation of the CGP synthesis in C. glutamicum has shown that C. glutamicum is a potentially interesting microorganism for CGP synthesis with a high content of alternative amino acids. This study shows that the amount of alternative amino acids can be increased by using mutants of C. glutamicum with altered amino acid biosynthesis. With the DM1729 mutant, the lysine content in the polymer could be increased up to 33.5 mol%. Furthermore, an ornithine content of up to 12.6 mol% was achieved with ORN2(Pgdh4). How much water-soluble or insoluble CGP is synthesized is strongly related to the used cyanophycin synthetase. CphADh synthesizes soluble CGP exclusively. However, soluble CGP could also be isolated from cells expressing CphA6308Δ1 or CphA6308Δ1_C595S in addition to insoluble CGP in all examined strains. The point mutation in CphA6308Δ1_C595S partially resulted in a higher lysine content. In addition, the CGP content could be increased to 36% of the cell dry weight under optimizing growth conditions in C. glutamicum ATCC13032. All known alternative major amino acids for CGP synthesis (lysine, ornithine, citrulline, and glutamic acid) could be incorporated into CGP in C. glutamicum.

scholarly journals A Water-Soluble Copper-Immobilized Covalent Organic Framework Functioning as an “OFF–ON” Fluorescent Sensor for Amino Acids

2021 ◽  
Author(s):  
Lamiaa Reda Ahmed ◽  
Ahmed F. M. EL-Mahdy ◽  
Cheng-Tang Pan ◽  
Shiao-Wei Kuo
Keyword(s):  
Amino Acids ◽  
Fluorescent Sensor ◽  
Water Soluble ◽  
One Pot ◽  
Covalent Organic Framework ◽  
The One ◽  
Organic Framework

In this paper, we describe the construction of a new fluorescent hydroxyl- and hydrazone-based covalent organic framework (TFPB-DHTH COF) through the one-pot polycondensation of 1,3,5-tris(4-formylphenyl)benzene (TFPB) and 2,5-dihydroxyterephthalohydrazide (DHTH) under...

scholarly journals Erratum to: Antibacterial Effects of Amino Acids-grafted Water-soluble Chitosan against Drug-resistant Bacteria

2021 ◽  
Vol 26 (3) ◽  
pp. 501-501
Author(s):  
Jun-Ho Kim ◽  
Nam-Hong Kim ◽  
Eun-Ji Kim ◽  
Ji Ho Kim ◽  
Min-Young Lee ◽  
...  
Keyword(s):  
Amino Acids ◽  
Water Soluble ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibacterial Effects ◽  
Drug Resistant Bacteria

scholarly journals Dietary Fiber, Atherosclerosis, and Cardiovascular Disease

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1155 ◽  
Author(s):  
Ghada A. Soliman
Keyword(s):  
Cardiovascular Disease ◽  
Dietary Fiber ◽  
Water Solubility ◽  
Disease Risk ◽  
Current Knowledge ◽  
Digestive Enzyme ◽  
Water Soluble ◽  
Blood Cholesterol ◽  
Fiber Intake ◽  
Intestinal Transit Time

Observational studies have shown that dietary fiber intake is associated with decreased risk of cardiovascular disease. Dietary fiber is a non-digestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber. Dietary fibers and lignin are intrinsic to plants and are classified according to their water solubility properties as either soluble or insoluble fibers. Water-soluble fibers include pectin, gums, mucilage, fructans, and some resistant starches. They are present in some fruits, vegetables, oats, and barley. Soluble fibers have been shown to lower blood cholesterol by several mechanisms. On the other hand, water-insoluble fibers mainly include lignin, cellulose, and hemicellulose; whole-grain foods, bran, nuts, and seeds are rich in these fibers. Water-insoluble fibers have rapid gastric emptying, and as such may decrease the intestinal transit time and increase fecal bulk, thus promoting digestive regularity. In addition to dietary fiber, isolated and extracted fibers are known as functional fiber and have been shown to induce beneficial health effects when added to food during processing. The recommended daily allowances (RDAs) for total fiber intake for men and women aged 19–50 are 38 gram/day and 25 gram/day, respectively. It is worth noting that the RDA recommendations are for healthy people and do not apply to individuals with some chronic diseases. Studies have shown that most Americans do not consume the recommended intake of fiber. This review will summarize the current knowledge regarding dietary fiber, sources of food containing fiber, atherosclerosis, and heart disease risk reduction.

Sign in / Sign up

Export Citation Format

Share Document