Search results for "De novo synthesis"
showing 9 items of 9 documents
2018
Many animals protect themselves from predation with chemicals, both self-made or sequestered from their diet. The potential drivers of the diversity of these chemicals have been long studied, but our knowledge of these chemicals and their acquisition mode is heavily based on specialist herbivores that sequester their defenses. The wood tiger moth (Arctia plantaginis, Linnaeus, 1758) is a well-studied aposematic species, but the nature of its chemical defenses has not been fully described . Here, we report the presence of two methoxypyrazines, 2-sec-butyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine, in the moths' defensive secretions. By raising larvae on an artificial diet, we confir…
Lipid droplets and autophagy-links and regulations from yeast to humans.
2021
Recent advances in the yeast Saccharomyces cerevisiae and higher eukaryotes have been increasingly connecting lipid droplet (LD) dynamics to the regulation of autophagy. In this review we will discuss implications that connect LD de novo synthesis and LD mobilization to autophagy and how autophagy is regulated by these mechanisms. Elucidating these connections might pose a chance to further understand autophagy induction and membrane biogenesis for the growing autophagosome under different conditions. Increasing our understanding of these mechanisms might provide a chance to understand several conditions that might be related to LD dysregulation and, possibly, as a consequence of this, dysr…
On-demand autophagic network adaptations upon limited lipid availability
2020
The de novo synthesis of autophagic vesicles is strongly dependent on sufficient lipid supply. Recently, the RAB GTPase RAB18 was shown to affect autophagy by mediating fatty acid release from lipid droplets, which are lipid sources for autophagosome formation. The stable loss of RAB18 interfered with fatty acid release from the lipid reservoirs and provoked autophagy network adaptations aiming to maintain autophagic activity under lipid limiting conditions.
Towards controlling PCDD/F production in a multi-fuel fired BFB boiler using two sulfur addition strategies. Part II: Thermodynamic analysis
2014
Abstract A staged equilibrium process model was developed for a bubbling fluidized bed boiler firing SRF, bark and sludge. The model was used to study the influence of sulfur addition strategies (S-pellet additive and peat co-firing) on the behavior of copper, bromine, and alkalis. Aerosol samples collected from the backpass of the boiler were used to validate the chemistry predicted by the model. The model revealed that Cu existed as Cu 2 S (s3) in the reducing zone, and CuCl (g) (for all test cases) and CuO (s) (during peat co-firing) in the oxidation zones. CuBr 3(g) was also present after the introduction of tertiary air. However the model failed to predict the formation of CuSO 4 , an …
Small Nitrogenous Compounds
1994
Because of the constant turnover of proteins, protein-bound and free amino acids exist in a dynamic equilibrium. The intracellular pool of free amino acids, which is replenished by the hydrolysis of existing proteins, by uptake from the intercellular space and by de novo synthesis, is available for protein synthesis and for the many other metabolic processes dependent upon amino acids. The concentration of free amino acids is always lower than that of the protein-bound residues, one limiting factor being the strong osmotic effects of such low molecular weight compounds. Thus, there is no specific amino acid store in an organism; it is more the case that enzymes and structural proteins thems…
The role of metal corrosion in inflammatory processes: induction of adhesion molecules by heavy metal ions
1994
Prosthetic devices undergo corrosion processes after implantation including the release of certain amounts of metal ions into the adjacent tissues. On reaching the bloodstream, a systemic influence of those ions may be envisaged. Cell adhesion molecules (CAMs) are recognized as an essential component of the mechanisms of endothelial damage. To study the influence of selected heavy metals on human umbilical vein endothelial cells (HUVEC) EIA methods were used to evaluate cellular expression of E-selectin, ICAM-1, VCAM-1 and GMP-140 under the influence of high (cytotoxic) very low (non-cytotoxic) concentrations of Zn, Ni, Co and Cr. The de novo synthesis of CAMs was studied with the help of m…
Modular De novo Synthesis of Unsymmetrical BODIPY Dyes Possessing Four Different Aryl Substituents
2017
A modular synthesis of unsymmetrical BODIPY dyes based on a [6π]-electrocyclization to construct the two pyrrole rings is presented. The products carry four aryl moieties in positions 1, 3, 5, and 7 which can be freely selected as well as optional substitution in positions 2 and 8. The method employs acetophenones, benzaldehydes as well as glycine nitrile or glycine ethyl ester as the key building blocks.
The ins and outs of cholesterol in the vertebrate retina
2010
Thematic Review Series: Lipids and Lipid Metabolism in the Eye; International audience; The vertebrate retina has multiple demands for utilization of cholesterol and must meet those demands either by synthesizing its own supply of cholesterol or by importing cholesterol from extraretinal sources, or both. Unlike the blood-brain barrier, the blood-retina barrier allows uptake of cholesterol from the circulation via a lipoprotein-based/receptor-mediated mechanism. Under normal conditions, cholesterol homeostasis is tightly regulated; also, cholesterol exists in the neural retina overwhelmingly in unesterified form, and sterol intermediates are present in minimal to negligible quantities. Howe…
The Homeostasis of Brain Choline
1993
The interest in the homeostasis of brain choline is reinforced by the role of choline as immediate precursor of acetylcholine, phosphatidylcholine and other phospholipids in the brain. In order to obtain a comprehensive view of the mochanisms of homeostasis it appeared necessary to elucidate the negative arteriovenous difference of choline across the brain (net release), a phenomenon that has been known for 20 years and is present in mammals and in man. This finding prompted an intense search for a de novo synthesis of choline in the brain. We detected in anaesthetized rats a reversal of the net release into a net uptake (positive arterio-venous difference), when the plasma level of choline…