Extrafloral nectaries that attract ants in Bromeliaceae: structure and nectar composition

1992 ◽  
Vol 70 (6) ◽  
pp. 1101-1106 ◽  
Author(s):  
Leonardo Galetto ◽  
Luis M. Bernardello
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Extrafloral Nectaries ◽  
Extrafloral Nectar ◽  
High Concentration ◽  
Nectar Composition ◽  
Anomocytic Stomata ◽  
Nectariferous Tissue ◽  
First Time ◽  
Very High

The occurrence of extrafloral nectaries in some species of Bromeliaceae (subfam. Pitcairnioideae) is reported for the first time in the following plants from central and northern Argentina: Deuterocohnia longipetala, Dyckia ferox, Dyckia floribunda, Dyckia aff. gilliesii, Dyckia ragonesei, and Dyckia velascana. Ants are attracted to the extrafloral nectar that is secreted in a very high concentration (around 80% weight to total weight) by nonstructural, nonvascularized nectaries located in the outer verticil of tepals. They do not possess a specially differentiated nectariferous tissue and the exudate is probably secreted through paracytic and anomocytic stomata. Sugars and amino acids were detected in the nectar, but alkaloids, reducing acids, proteins, phenols, and lipids were not. Amino acid concentration ranged from 121.3 to 975 μg/mL. In all the species there was a high concentration of sucrose (97.2–100%), whereas glucose and (or) fructose were absent or present in a small amount (0.4–1.5%). Key words: Bromeliaceae, extrafloral nectaries, structure, nectar composition, ants.

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.

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...

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 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.

Growth responses of race 222 of Puccinia graminis tritici in defined media

1982 ◽  
Vol 28 (5) ◽  
pp. 486-492
Author(s):  
Hardev Singh ◽  
Inderjeet Sethi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Axenic Culture ◽  
Puccinia Graminis ◽  
Growth Responses ◽  
Liquid Media ◽  
High Concentration ◽  
Puccinia Graminis Tritici ◽  
Defined Media

Aseptically produced uredospores of race 222 of Puccinia graminis tritici were seeded on defined liquid media containing Czapek's minerals, sucrose or glucose, and various combinations and concentrations of 19 amino acids and a tripeptide, glutathione. The cultures were incubated in the dark at 16–17 °C. A medium containing a high concentration of aspartic acid (5988 ppm), cysteine (557 ppm), and glutathione (1014 ppm) supported a profuse growth of the fungus in the form of floating white, fluffy, and vegetative colonies. A sulphur-containing amino acid appears to be essential for the axenic culture of the fungus.

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 Gustatory responses of eel palatine receptors to amino acids and carboxylic acids.

1979 ◽  
Vol 74 (3) ◽  
pp. 301-317 ◽  
Author(s):  
K Yoshii ◽  
N Kamo ◽  
K Kurihara ◽  
Y Kobatake
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acids ◽  
Carbon Chain ◽  
Threshold Concentration ◽  
The Other ◽  
Carbon Chain Length ◽  
High Concentration ◽  
Gustatory Receptors ◽  
Cross Adaptation

The gustatory receptors of the eel palate were found to be extremely sensitive to amino acids and carboxylic acids. The results obtained are as follows: (a) 11 amino acids which are among naturally occurring amino acids elicited responses in the palatine nerve, but 9 amino acids did not elicit a response even at a high concentration. The effect of D-amino acids was always much less than that of their corresponding L-isomers. There was no appreciable difference in the effectiveness of an alpha-amino acid (alpha-alanine) and beta-amino acid (beta-alanine). (b) The threshold concentrations of the most potent amino acids (arginine, glycine) were between 10(-8) and 10(-9) M. A linear relation between the magnitude of the response and log stimulus concentration held for a wide concentration range for all the amino acids examined. (c) The palatine receptors responded sensitively to various carboxylic acid solutions whose pH was adjusted to neutral. The threshold concentrations varied between 10(-4) and 10(-7) M. The magnitude of the response at 10(-2) M increased with an increase of carbon chain length. (d) The extent of cross-adaptation was examined with various combinations of amino acids. A variety of the response patterns showing complete cross-adaptation, no cross-adaptation, or synergetic interaction was observed. The synergetic interaction was also observed when one amino acid below its threshold concentration was added to the other amino acid below its threshold concentration was added to the other amino acid. No cross-adaptation was observed between amino acids and fatty acids. (e) The treatment of the palate with papain led to loss of the responses to arginine, glycine, and histidine without affecting those to proline and acetic acid. The treatment with pronase E eliminated selectively the response to proline. The possibility that the eel gustatory receptors are responsible for sensing food at a distance was discussed.

scholarly journals Cytochrome C and COI Sequence of O.laetus Review

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Mazhar MW ◽  
◽  
Raza A ◽  
Sikandar M ◽  
Mahmood J ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Coi Gene ◽  
Accession Number ◽  
Protein Entry ◽  
Significant Match ◽  
Very High

The COI sequence of O.laetus was submitted to the Genbank database holding an accession number HQ908084 (Figure1). The amino acid sequence of the corresponding COI gene was also updated under the accession number ADZ05746, which turned out to contain 222 amino acids. Base statistics of the O.laetus COI are presented in Figure 2. It can be seen from the table that the fragment is rich in AT content as expected with thymine occurring most frequently followed by the others in the order A, C & G. The AT% stood at 67.2 in comparison to GC% at 32.8. The protein entry was subjected to family confirmation by searching the InterProScan database and the results indicate a very high and significant match confirming our sequence to be a part of Cytochrome C.

scholarly journals BIOLOGICAL VALUE OF PROTEINS OF MILK OF SIMMENTAL COWS PRODUCED UNDER CONDITIONS OF INTENSIVE TECHNOLOGY

2021 ◽  
Vol 247 (3) ◽  
pp. 288-292
Author(s):  
L.G. Khromova ◽  
◽  
N.V. Bailova ◽  
A.I. Sychev ◽  
◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Oscillation Amplitude ◽  
Essential Amino Acids ◽  
Acid Number ◽  
Protein Component ◽  
High Concentration ◽  
Biological Value ◽  
Amino Acid Index ◽  
Acid Index

Taking into account modern requirements, the biological value of the protein component of the Simmental breed Krov milk produced under intensive technology has been studied. The amino acid composition of milk proteins was identified by high-performance liquid chromatography. To analyze the biological value of proteins, calculated indicators were used: the amino acid index and the amino acid number (skor) of essential amino acids, taking into account the true digestibility of each of them. As a result of the research, all the essential and interchangeable amino acids and a fairly high concentration of many of them were identified. Among the essential amino acids, the largest amount in the milk samples contained phenylalanine+tyrosine, leucine, lysine, valine, and the smallest-tryptophan, methionine+cysteine. In the aggregate of interchangeable amino acids, the highest saturation was noted for glutamic acid+glutamine, arginine, proline, and the lowest-glycine, alanine. The predominance of interchangeable amino acids was noted in the protein component, which caused a low amino acid index (0.61). The amount of assimilated essential amino acids was higher relative to the reference protein. However, the amino acid score had a wide oscillation amplitude: from 149.6 % for the amino acids phenylalanine + tyrosine to 61.2 and 87.8 %, respectively, for tryptophan and methionine+cysteine, which indicated their imbalance. The essential amino acids tryptophan and methionine+cysteine were limiting, since their amino acid number (skor) is below 100 %.

scholarly journals A new congenital abnormal fibrinogen Ise characterized by the replacement of B beta glycine-15 by cysteine

Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1958-1963 ◽  
Author(s):  
N Yoshida ◽  
H Wada ◽  
K Morita ◽  
H Hirata ◽  
M Matsuda ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Reversed Phase ◽  
Polymerization Reaction ◽  
Thrombin Time ◽  
Beta Chain ◽  
High Concentration ◽  
Elution Pattern ◽  
Peptide Peak ◽  
Very High

Abstract A new case of heterozygous dysfibrinogenemia characterized by the replacement of NH2-terminal amino acid of fibrin beta-chain was found in a 50-year-old man. Despite a prolonged thrombin time, the propositus' fibrinogen had a normal reptilase time with the normal release of fibrinopeptide A. Release of fibrinopeptide B by thrombin was strongly affected, but a very high concentration of thrombin almost completely released fibrinopeptide B with a normal elution pattern on reversed-phase high performance liquid chromatography (HPLC). Lysylendopeptidase-cleavage of purified B beta-chains analyzed on HPLC showed the decrease of one peptide compared with the normal and the appearance of an abnormal peptide peak. These peptides were treated with thrombin and further separated on HPLC. Amino acid sequence analysis of the abnormal peptide demonstrated that B beta glycine-15, NH2-terminus of the fibrin beta-chain, was replaced by cysteine. These findings will be of particular importance because they strongly support the hypothesis that the NH2-terminal portion of the fibrin beta-chain is involved in the polymerization reaction by thrombin. The propositus' daughter and two sisters had the same abnormal fibrinogen. This unique inherited abnormal fibrinogen was designated as fibrinogen Ise. During these studies, we found that a very high concentration of thrombin cleaves not only the A alpha Arg19-Val20 bond but also the COOH- terminal region of alpha-chains, which results in the generation of further degraded alpha-chains with apparent molecular weights of 44,000 or less.

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