scholarly journals Tracing the Trophic Plasticity of the Coral–Dinoflagellate Symbiosis Using Amino Acid Compound-Specific Stable Isotope Analysis

2021 ◽  
Vol 9 (1) ◽  
pp. 182
Author(s):  
Christine Ferrier-Pagès ◽  
Stephane Martinez ◽  
Renaud Grover ◽  
Jonathan Cybulski ◽  
Eli Shemesh ◽  
...  
Keyword(s):  
Amino Acids ◽  
Essential Role ◽  
Isotope Analysis ◽  
Diagnostic Tools ◽  
Global Changes ◽  
Biosynthetic Pathways ◽  
Trophic Plasticity ◽  
Trophic Index ◽  
Δ15n And Δ13c ◽  
Acid Compound

The association between corals and photosynthetic dinoflagellates is one of the most well-known nutritional symbioses, but nowadays it is threatened by global changes. Nutritional exchanges are critical to understanding the performance of this symbiosis under stress conditions. Here, compound-specific δ15N and δ13C values of amino acids (δ15NAA and δ13CAA) were assessed in autotrophic, mixotrophic and heterotrophic holobionts as diagnostic tools to follow nutritional interactions between the partners. Contrary to what was expected, heterotrophy was mainly traced through the δ15N of the symbiont’s amino acids (AAs), suggesting that symbionts directly profit from host heterotrophy. The trophic index (TP) ranged from 1.1 to 2.3 from autotrophic to heterotrophic symbionts. In addition, changes in TP across conditions were more significant in the symbionts than in the host. The similar δ13C-AAs signatures of host and symbionts further suggests that symbiont-derived photosynthates are the main source of carbon for AAs synthesis. Symbionts, therefore, appear to be a key component in the AAs biosynthetic pathways, and might, via this obligatory function, play an essential role in the capacity of corals to withstand environmental stress. These novel findings highlight important aspects of the nutritional exchanges in the coral–dinoflagellates symbiosis. In addition, they feature δ15NAA as a useful tool for studies regarding the nutritional exchanges within the coral–symbiodiniaceae symbiosis.

scholarly journals Organic Carbon and Nitrogen Isoscapes of Reef Corals and Algal Symbionts: Relative Influences of Environmental Gradients and Heterotrophy

2020 ◽  
Vol 8 (8) ◽  
pp. 1221
Author(s):  
Takanori Fujii ◽  
Yasuaki Tanaka ◽  
Koh Maki ◽  
Nobue Saotome ◽  
Naoko Morimoto ◽  
...  
Keyword(s):  
Amino Acids ◽  
Environmental Gradients ◽  
Diagnostic Tools ◽  
Ecological Niches ◽  
Δ13c And Δ15n ◽  
Δ13c Values ◽  
Algal Symbionts ◽  
Coral Health ◽  
Endosymbiotic Algae ◽  
Δ15n And Δ13c

The elemental (C/N) and stable isotopic (δ13C, δ15N) compositions and compound-specific δ15N values of amino acids (δ15NAA) were evaluated for coral holobionts as diagnostic tools to detect spatiotemporal environmental heterogeneity and its effects on coral health. Hermatypic coral samples of eight species were collected at 12 reef sites with differing levels of pollution stress. The C/N ratios, δ13C values, and δ15N values of coral tissues and endosymbiotic algae were determined for 193 coral holobionts, and the amino acid composition and δ15NAA values of selected samples were analyzed. δ15N values were influenced most by pollution stress, while C/N ratios and δ13C values depended most strongly on species. The results imply that δ13C and δ15N values are useful indicators for distinguishing the ecological niches of sympatric coral species based on microhabitat preference and resource selectivity. Using δ15NAA values, the trophic level (TL) of the examined coral samples was estimated to be 0.71 to 1.53, i.e., purely autotrophic to partially heterotrophic. Significant portions of the variation in bulk δ15N and δ13C values could be explained by the influence of heterotrophy. The TL of symbionts covaried with that of their hosts, implying that amino acids acquired through host heterotrophy are translocated to symbionts. Dependence on heterotrophy was stronger at polluted sites, indicating that the ecological role of corals changes in response to eutrophication.

scholarly journals Meroterpenoids: A Comprehensive Update Insight on Structural Diversity and Biology

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 957
Author(s):  
Mamona Nazir ◽  
Muhammad Saleem ◽  
Muhammad Imran Tousif ◽  
Muhammad Aijaz Anwar ◽  
Frank Surup ◽  
...  
Keyword(s):  
Amino Acids ◽  
Secondary Metabolites ◽  
Biological Effects ◽  
Structural Diversity ◽  
Chemical Diversity ◽  
Biosynthetic Pathways ◽  
Natural Sources ◽  
Hybrid Compounds ◽  
Anti Inflammatory

Meroterpenoids are secondary metabolites formed due to mixed biosynthetic pathways which are produced in part from a terpenoid co-substrate. These mixed biosynthetically hybrid compounds are widely produced by bacteria, algae, plants, and animals. Notably amazing chemical diversity is generated among meroterpenoids via a combination of terpenoid scaffolds with polyketides, alkaloids, phenols, and amino acids. This review deals with the isolation, chemical diversity, and biological effects of 452 new meroterpenoids reported from natural sources from January 2016 to December 2020. Most of the meroterpenoids possess antimicrobial, cytotoxic, antioxidant, anti-inflammatory, antiviral, enzyme inhibitory, and immunosupressive effects.

scholarly journals Stable nitrogen isotope analysis of amino acids as a new tool to clarify complex parasite–host interactions within food webs

Oikos ◽  
2021 ◽  
Author(s):  
Philip M. Riekenberg ◽  
Tijs Joling ◽  
Lonneke L. IJsseldijk ◽  
Andreas M. Waser ◽  
Marcel T. J. van der Meer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Food Webs ◽  
Isotope Analysis ◽  
Nitrogen Isotope ◽  
Stable Nitrogen Isotope ◽  
Host Interactions ◽  
Nitrogen Isotope Analysis

Essential role of amino acids in αD–β4 loop of a Bacillus thuringiensis Cyt2Aa2 toxin in binding and complex formation on lipid membrane

Toxicon ◽  
2013 ◽  
Vol 74 ◽  
pp. 130-137 ◽  
Author(s):  
Kunat Suktham ◽  
Wanwarang Pathaichindachote ◽  
Boonhiang Promdonkoy ◽  
Chartchai Krittanai
Keyword(s):  
Amino Acids ◽  
Bacillus Thuringiensis ◽  
Complex Formation ◽  
Essential Role ◽  
Lipid Membrane

Compound-Specific δ15N and δ13C Analyses of Amino Acids for Potential Discrimination between Organically and Conventionally Grown Wheat

2015 ◽  
Vol 63 (25) ◽  
pp. 5841-5850 ◽  
Author(s):  
Mauro Paolini ◽  
Luca Ziller ◽  
Kristian Holst Laursen ◽  
Søren Husted ◽  
Federica Camin
Keyword(s):  
Amino Acids ◽  
Δ15n And Δ13c

Biosynthesis of Carbohydrates and Amino Acids

2016 ◽  
Author(s):  
Gary W. Morrow
Keyword(s):  
Amino Acids ◽  
Construction Materials ◽  
Building Blocks ◽  
General Term ◽  
Molecular Formula ◽  
Biosynthetic Pathways ◽  
Hydrated Form ◽  
The Core ◽  
Carbon Dioxide Co2 ◽  
Structure And Metabolism

We have already seen that some of the basic building blocks used in the biosynthesis of natural products are amino acids such as phenylalanine, tyrosine, and others. These and other crucial construction materials such as the acyl group in acetyl-CoA are all ultimately derived from carbohydrates. In this chapter, we will present an abbreviated overview of the components of carbohydrate structure and metabolism sufficient for our purposes going forward, with a schematic flowchart showing how carbohydrates and amino acids are modified, combined, and branched off in various ways to yield the distinct set of biosynthetic pathways that will form the core of the remainder of the text. We will finish the chapter with a brief, general review of amino acid nomenclature and structure with emphasis on the key amino acids that will be used throughout the remainder of the text. We know that plants make glucose (C6H12O6) by photosynthesis using light, water (H2O), and carbon dioxide (CO2). Another way of looking at the formula for glucose is C6(H2O)6, that is, six carbon atoms and six water molecules. Thus, glucose was originally referred to as a hydrated form of carbon—a carbohydrate. But this is a very general term since there are many different types of carbohydrate compounds. One way to broadly classify carbohydrates is to identify them as either mono- (one), di- (two), oligo- (a few) or poly- (many) saccharides. For example, glucose (C6H12O6) cannot be broken down into simpler carbohydrates by simple hydrolysis, so it is classified as a monosaccharide, that is, a single, discrete carbohydrate compound. On the other hand, the carbohydrate sucrose (C12H22O11) is classified as a disaccharide since when it is subjected to aqueous hydrolysis, it yields two different monosaccharide carbohydrates, namely glucose (C6H12O6) and fructose (C6H12O6). Noting that glucose and fructose are different compounds but with the same molecular formula, they must be related to one another either as stereoisomers or as constitutional isomers, so further refinement of classification is needed. Structurally speaking, most monosaccharide carbohydrates are simply polyhydroxyaldehydes (aldoses) or polyhydroxyketones (ketoses) which can be further classified using a combination of aldo- or keto- prefixes along with suffixes such as triose, tetrose, pentose, or hexose to designate the number of carbon atoms.

scholarly journals Stable Isotope Enrichment (Δ15N) in the Predatory Flower Bug (Orius majusculus) Predicts Fitness-Related Differences between Diets

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 255
Author(s):  
Marta Montoro ◽  
Per M. Jensen ◽  
Lene Sigsgaard
Keyword(s):  
Diet Quality ◽  
Isotopic Ratio ◽  
Isotope Analysis ◽  
Mass Rearing ◽  
Isotope Enrichment ◽  
Orius Majusculus ◽  
Food And Feed ◽  
The Difference ◽  
Biochemical Analyses ◽  
Δ15n And Δ13c

Mass rearing of insects, used both as biological control agents and for food and feed, is receiving increasing attention. Efforts are being made to improve diets that are currently in use, and to identify alternative diets, as is the case with the predatory flower bug (Orius majusculus) and other heteropteran predators, due to the high costs of their current diet, the eggs of the Mediterranean flour moth (E. kuehniella). The assessment of alternative diets may include measurements of the predator’s fitness-related traits (development time, weight, etc.), and biochemical analyses such as lipid and protein content in the diet and the insects. However, assessing diet quality via the predator’s fitness-related traits is laborious, and biochemical composition is often difficult to relate to the measured traits. Isotope analysis, previously used for diet reconstruction studies, can also serve as a tool for the assessment of diet quality. Here, the variation in discrimination factors or isotope enrichment (Δ15N and Δ13C) indicates the difference in isotopic ratio between the insect and its diet. In this study, we investigated the link between Δ15N and diet quality in the predatory bug Orius majusculus. Three groups of bugs were fed different diets: Ephestia kuehniella eggs, protein-rich Drosophila melanogaster and lipid-rich D. melanogaster. The isotopic enrichment and fitness-related measurements were assessed for each group. Results show a relation between Δ15N and fitness-related measurements, which conform to the idea that lower Δ15N indicates a higher diet quality.

scholarly journals Natural Isotope Abundances of Carbon and Nitrogen in Tissue Proteins and Amino Acids as Biomarkers of the Decreased Carbohydrate Oxidation and Increased Amino Acid Oxidation Induced by Caloric Restriction under a Maintained Protein Intake in Obese Rats

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1087 ◽  
Author(s):  
Jean-François Huneau ◽  
Olivier L. Mantha ◽  
Dominique Hermier ◽  
Véronique Mathé ◽  
Guillaume Galmiche ◽  
...  
Keyword(s):  
Amino Acids ◽  
Caloric Restriction ◽  
Protein Intake ◽  
Skeletal Muscles ◽  
Acid Oxidation ◽  
Protein Mass ◽  
Obese Rats ◽  
Lower Protein ◽  
Underlying Mechanisms ◽  
Δ15n And Δ13c

A growing body of evidence supports a role for tissue-to-diet 15N and 13C discrimination factors (Δ15N and Δ13C), as biomarkers of metabolic adaptations to nutritional stress, but the underlying mechanisms remain poorly understood. In obese rats fed ad libitum or subjected to gradual caloric restriction (CR), under a maintained protein intake, we measured Δ15N and Δ13C levels in tissue proteins and their constitutive amino acids (AA) and the expression of enzymes involved in the AA metabolism. CR was found to lower protein mass in the intestine, liver, heart and, to a lesser extent, some skeletal muscles. This was accompanied by Δ15N increases in urine and the protein of the liver and plasma, but Δ15N decreases in the proteins of the heart and the skeletal muscles, alongside Δ13C decreases in all tissue proteins. In Lys, Δ15N levels rose in the plasma, intestine, and some muscles, but fell in the heart, while in Ala, and to a lesser extent Glx and Asx, Δ13C levels fell in all these tissues. In the liver, CR was associated with an increase in the expression of genes involved in AA oxidation. During CR, the parallel rises of Δ15N in urine, liver, and plasma proteins reflected an increased AA catabolism occurring at the level of the liver metabolic branch point, while Δ15N decreases in cardiac and skeletal muscle proteins indicated increased protein and AA catabolism in these tissues. Thus, an increased protein and AA catabolism results in opposite Δ15N effects in splanchnic and muscular tissues. In addition, the Δ13C decrease in all tissue proteins, reflects a reduction in carbohydrate (CHO) oxidation and routing towards non-indispensable AA, to achieve fuel economy.

scholarly journals Divergent architecture of the heterotrimeric NatC complex explains N-terminal acetylation of cognate substrates

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephan Grunwald ◽  
Linus V. M. Hopf ◽  
Tobias Bock-Bierbaum ◽  
Ciara C. M. Lally ◽  
Christian M. T. Spahn ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Essential Role ◽  
Catalytic Mechanism ◽  
Detailed Structure ◽  
Auxiliary Subunits ◽  
Target Proteins ◽  
Ribosome Binding ◽  
Specific Ligand

Abstract The heterotrimeric NatC complex, comprising the catalytic Naa30 and the two auxiliary subunits Naa35 and Naa38, co-translationally acetylates the N-termini of numerous eukaryotic target proteins. Despite its unique subunit composition, its essential role for many aspects of cellular function and its suggested involvement in disease, structure and mechanism of NatC have remained unknown. Here, we present the crystal structure of the Saccharomyces cerevisiae NatC complex, which exhibits a strikingly different architecture compared to previously described N-terminal acetyltransferase (NAT) complexes. Cofactor and ligand-bound structures reveal how the first four amino acids of cognate substrates are recognized at the Naa30–Naa35 interface. A sequence-specific, ligand-induced conformational change in Naa30 enables efficient acetylation. Based on detailed structure–function studies, we suggest a catalytic mechanism and identify a ribosome-binding patch in an elongated tip region of NatC. Our study reveals how NAT machineries have divergently evolved to N-terminally acetylate specific subsets of target proteins.

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