Access to 2-Arylquinazolines via Catabolism/Reconstruction of Amino Acids with Insertion of Dimethyl Sulfoxide

2021 ◽  
Author(s):  
Jin-Tian Ma ◽  
Li-Sheng Wang ◽  
Zhi Chai ◽  
Xin-Feng Chen ◽  
Bo-Cheng Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Source ◽  
Carbon And Nitrogen ◽  
First Time

Quinazoline skeletons are synthesized by amino acids catabolism/reconstruction combined with dimethyl sulfoxide insertion/cyclization for the first time. The amino acid acts as a carbon and nitrogen source through HI-mediated catabolism...

Utilization of single L-amino acids as sole source of carbon and nitrogen by bacteria

1972 ◽  
Vol 18 (11) ◽  
pp. 1647-1650 ◽  
Author(s):  
Harvest Halvorson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Source ◽  
Sole Source ◽  
Nutrient Agar ◽  
Single Amino Acid ◽  
Field Soil ◽  
Carbon And Nitrogen ◽  
Large Numbers ◽  
Ecological Aspects

The utilization of single L-amino acids as sole source of carbon and nitrogen by bacteria was studied and was found to be very common and widely distributed over many genera. Field soil contained large numbers of such bacteria; 7.7–79.2% of the colony count obtained on nutrient agar could be achieved by using a single amino acid as sole carbon and nitrogen source. Twenty taxonomically known bacteria which could use one or more amino acids were examined for the range of amino acids over which they could grow. Organisms which grew on one amino acid usually grew on several. Some ecological aspects of these findings are discussed.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

On the Possible Spatial Structures of the β – Amyloid.

2022 ◽  
Vol 7 (1) ◽  
pp. 0-0
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Spatial Structure ◽  
Spatial Models ◽  
Globular Proteins ◽  
Spatial Structures ◽  
Higher Dimensional ◽  
Protein Molecules ◽  
Β Amyloid ◽  
First Time

Spatial models of the β - structures of protein molecules, forming layers of amino acids, in principle, of unlimited length for both antiparallel and parallel conformation have been constructed. It is shown that the simplified flat Pauling models do not reflect the spatial structure of these layers. Using the recently developed theory of higher-dimensional polytopic prismahedrons, models of the volumetric filling of space with amino acid molecules are constructed. The constructed models for the first time mathematically describe the native structures of globular proteins.

scholarly journals Mechanisms for Induction of Microbial Extracellular Proteases in Response to Exterior Proteins

2020 ◽  
Vol 86 (19) ◽  
Author(s):  
Yu-Zhong Zhang ◽  
Wei-Xin Zhang ◽  
Xiu-Lan Chen
Keyword(s):  
Amino Acids ◽  
Nitrogen Source ◽  
Organic Nitrogen ◽  
Nutrient Acquisition ◽  
Extracellular Proteases ◽  
Carbon And Nitrogen ◽  
Heterotrophic Microorganisms ◽  
Organic Nitrogen Source ◽  
Host Infection ◽  
Made In

ABSTRACT Proteins are a main organic nitrogen source for microorganisms. Many heterotrophic microorganisms secrete extracellular proteases (ex-proteases) to efficiently decompose proteins into oligopeptides and amino acids when exterior proteins are required for growth. These ex-proteases not only play important roles in microbial nutrient acquisition or host infection but also contribute greatly to the global recycling of carbon and nitrogen. Moreover, may microbial ex-proteases have important applications in industrial, medical, and biotechnological areas. Therefore, uncovering the mechanisms by which microorganisms initiate the expression of ex-protease genes in response to exterior proteins is of great significance. In this review, the progress made in understanding the induction mechanisms of microbial ex-proteases in response to exterior proteins is summarized, with a focus on the inducer molecules, membrane sensors, and downstream pathways. Problems to be solved for better understanding of the induction mechanisms of microbial ex-proteases are also discussed.

scholarly journals Bakerian lecture - Amino-acid analysis and the structure of proteins

1942 ◽  
Vol 131 (863) ◽  
pp. 136-160 ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Nutritive Value ◽  
Analytical Data ◽  
Seed Proteins ◽  
Decomposition Products ◽  
First Time ◽  
Structure Of Proteins

In recent years the X-ray crystallographers have made remarkable advances in the interpretation of protein structure, and it is becoming more and more evident that a stage has been reached when their views need to be reconciled with data obtained from accurate amino-acid analysis of the proteins concerned. In all too many cases these data are, unfortunately, not yet available, and the reason why the analyst cannot supply them at short notice is due not so much to the com­plexity of the problem—which he has never sought to minimize—but to the fact that many of the more important methods of analysis in current use are an inheritance from an earlier period when such accuracy as is now demanded would have been considered almost impossible of achievement. From about 1840 until 1900, following the lead given by Liebig and later by Ritthausen, the attention of protein chemists was centred chiefly on the prepara­tion and characterization of various animal and seed proteins; as substances of physiological interest their enzymic digestion products were studied in elaborate detail by Kühne, but little attention was paid to the ultimate decomposition products, the amino-acids, in spite of the fact that Ritthausen as early as 1872 had pointed out that the proportions in which these occur might be characteristic of the protein concerned. The enunciation by Hofmeister and Fischer of the peptide hypothesis in 1901 emphasized for the first time the fundamental importance of the amino-acids, and a most fruitful period followed in which attention became almost exclusively focused on these products. Under the inspiring leadership of Fischer himself great improvements were effected in the separation and identification of the amino-acids, so that by about 1915 reasonably good analyses were available for most of the better-known proteins. Though far from complete, the analytical data showed quite clearly that proteins could differ widely in composition, and in many cases it was possible to correlate composition with nutritive value. Such an aim was, indeed, the incentive behind much of the work of this period.

scholarly journals Brooding fathers, not siblings, take up nutrients from embryos

2009 ◽  
Vol 277 (1683) ◽  
pp. 971-977 ◽  
Author(s):  
Gry Sagebakken ◽  
Ingrid Ahnesjö ◽  
Kenyon B. Mobley ◽  
Inês Braga Gonçalves ◽  
Charlotta Kvarnemo
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nutrient Uptake ◽  
Muscle Tissue ◽  
Brood Pouch ◽  
The Other ◽  
Syngnathus Typhle ◽  
Brooding Period ◽  
Male Brood ◽  
First Time

It is well known that many animals with placenta-like structures provide their embryos with nutrients and oxygen. However, we demonstrate here that nutrients can pass the other way, from embryos to the parent. The study was done on a pipefish, Syngnathus typhle , in which males brood fertilized eggs in a brood pouch for several weeks. Earlier research has found a reduction of embryo numbers during the brooding period, but the fate of the nutrients from these ‘reduced’ embryos has been unknown. In this study, we considered whether (i) the brooding male absorbs the nutrients, (ii) siblings absorb them, or (iii) a combination of both. Males were mated to two sets of females, one of which had radioactively labelled eggs (using 14 C-labelled amino acids), such that approximately half the eggs in the brood pouch were labelled. This allowed us to trace nutrient uptake from these embryos. We detected that 14 C-labelled amino acids were transferred to the male brood pouch, liver and muscle tissue. However, we did not detect any significant 14 C-labelled amino-acid absorption by the non-labelled half-siblings in the brood pouch. Thus, we show, to our knowledge, for the first time, that males absorb nutrients derived from embryos through their paternal brood pouch.

scholarly journals Characterization of a Novel Type Homoserine Dehydrogenase Only with High Oxidation Activity from Arthrobacter nicotinovorans

2021 ◽  
Author(s):  
Xinxin Liang ◽  
Huaxiang Deng ◽  
Yajun Bai ◽  
Tai-Ping Fan ◽  
Xiaohui Zheng ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nitrogen Source ◽  
Aspartic Acid ◽  
Molecular Mechanisms ◽  
Feedback Inhibition ◽  
Physiological Role ◽  
Homoserine Dehydrogenase ◽  
Oxidation Activity ◽  
Carbon And Nitrogen ◽  
Arthrobacter Nicotinovorans

AbstractHomoserine dehydrogenase (HSD) is a key enzyme in the synthesis pathway of the aspartate family of amino acids. HSD can catalyze the reversible reaction of L-aspartate-β-semialdehyde (L-ASA) to L-homoserine (L-Hse). In direct contrast, growth characteristic studies of some bacterial such as Arthrobacter nicotinovorans showed that the bacterium could grow well in medium with L-homoserine as sole carbon, nitrogen and energy source, but the genes responsible for the degradation of L-Hse remain unknown. Based on the function and sequence analysis of HSD, one putative homoserine dehydrogenase from A.nicotinovorans was named AnHSD, which was different from those HSDs that from the aspartic acid metabolic pathway, might be responsible for the degradation of L-Hse. Surprisingly, the analysis showed that the purified AnHSD exhibited specific L-Hse oxidation activity without reducing activity. At pH 10.0 and 40 °C, The Km and Kcat of AnHSD was 6.30 ± 1.03 mM and 462.71 s-1, respectively. AnHSD was partiality for NAD+ cofactor, as well as insensitive to feedback inhibition of downstream amino acids of aspartic acid family. The physiological role of AnHSD in A.nicotinovorans is discussed. These findings provide a novel insight for a better understanding of an alternative genetic pathway for L-Hse catabolism which was dominated by the novel HSD.ImportanceL-homoserine is an important building block for the synthesis of L-threonine, L-methionine, L-lysine which from aspartic acid family amino acids. However, some bacteria can make use of L-homoserine as a sole carbon and nitrogen source. Although the microbial degradation of L-homoserine has been studied several times, the genes involved and the molecular mechanisms remain unclear. In this study, we show that AnHSD responsible for the catabolism of L-homoserine in strain Arthrobacter nicotinovorans, as a special homoserine dehydrogenase with high diversity exists in Arthrobacter, Microbacterium, Rhizobium. We report for the first time that this novel homoserine dehydrogenase is now proposed to play a crucial role in that L-homoserine can use as a sole carbon and nitrogen source. This study is aimed at elucidating the enzymatic properties and function features of homoserine dehydrogenase from Arthrobacter nicotinovorans. These findings provide new insight into the catabolism of L-homoserine in bacteria.

The effect of pH and amino acids on conidiation and pigment production of Monascus major ATCC 16362 and Monascus rubiginosus ATCC 16367 in submerged shaken culture

1978 ◽  
Vol 24 (11) ◽  
pp. 1346-1357 ◽  
Author(s):  
Mariette Carels ◽  
David Shepherd
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Source ◽  
Yeast Extract ◽  
Amino Acid Mixture ◽  
Pigment Production ◽  
Ammonium Uptake ◽  
Acid Mixture ◽  
Medium Components ◽  
Conidial Formation

Monascus major ATCC 16362 and Monascus rubiginosus ATCC 16367 were cultivated aerobically on media containing nitrate or ammonium as nitrogen source to which the following modifications were made: (1) pH adjusted to 2.5 before sterilization; (2) addition of yeast extract; (3) addition of amino acids in identical proportions and concentrations to those found in yeast extract; (4) adjustment of pH to 2.5 after addition of amino acids.The addition of amino acids in the form of yeast extract increased mycelium formation and reduced conidiation and pigment production. The addition of an amino acid mixture did not increase mycelium formation to the same extent as yeast extract but increased the number of conidia, while pigment production was reduced, especially when nitrate was the nitrogen source. As the amino acids are taken up after conidial formation has started, it would appear that it is not the amino acids themselves which are directly responsible for the induction of conidiation. The addition of amino acids inhibits nitrate and ammonium uptake suggesting the need for an early intracellular nitrogen limitation to induce conidiation. Lowering the pH inhibits the formation of conidia and increases pigment production; also the effect of amino acid addition is totally annulled.The pH of the medium is all important in regulating the formation of conidia and pigment production. The possible effects of the pH on the uptake of certain medium components is discussed, as well as their possible control of certain metabolic pathways which ultimately determines the availability of intermediates for conidiation and pigment production.

AMINO ACIDS AND UTILIZATION OF SODIUM CASEINATE BY LACTIC STREPTOCOCCI

1957 ◽  
Vol 3 (3) ◽  
pp. 487-491 ◽  
Author(s):  
I. Husain ◽  
I. J. McDonald
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Source ◽  
Sodium Caseinate ◽  
Amino Acid Requirements ◽  
Sparing Effect

The ability of strains of lactic streptococci to utilize unhydrolyzed sodium caseinate as the nitrogen source in an otherwise complete, chemically denned medium did not appear to be related to their minimal amino acid requirements. Sodium caseinate had a sparing effect on the requirement for some amino acids of some strains of streptococci that did not use caseinate, but the amino acids spared varied with the strain. However, leucine, isoleucine, methionine, and valine appeared to be essential for this group of organisms in the presence or absence of sodium caseinate.

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