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.

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...

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.

Spatial Structures and Trends of Cities in Europe and Asia:  A Joint Methodological Approach Based on the Global Human Settlement Layer

2020 ◽  
Vol 11 (2) ◽  
pp. 195-217
Author(s):  
Debolina Kundu ◽  
Andre Mueller ◽  
Volker Schmidt-Seiwert ◽  
Regine Binot ◽  
Lukas Kiel ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Growth Pattern ◽  
Sustainable Development Goals ◽  
Methodological Approach ◽  
Spatial Structures ◽  
Developing Regions ◽  
Development Goals ◽  
First Time ◽  
Indian Cities ◽  
New Urban Agenda

Human civilization reached a milestone in the first decade of the 21st century, when the global urban population became higher than rural for the first time. However, the process of urbanisation is not uniform across the globe, and striking differences exist in the spatial structure and trends of urbanisation in developed and developing regions because of varying rates of demographic and economic growth. The success of Sustainable Development Goals (SDGs) depends on addressing urbanisation challenges with comparative knowledge of the spatial structure and growth pattern of the cities across regions. In this context, the present study examines the spatial structures and urbanisation trends of cities in Asia and Europe through standardised data and visualisation, with particular reference to India and Germany. The results show that ‘shrinking cities’ are more common in Europe and particularly in Germany. In contrast, Indian cities have registered an overall increase in population of cities, although at a slower growth rate. Also, the rate of growth of the built-up areas is relatively higher in India than Europe. However, both these geographies are experiencing higher growth of built-up areas as compared to population. A detailed analysis of the built-up areas in select cities of Europe and India in different time-periods reveals the cities’ growth pattern to be aligned with transport routes. The study concludes that developing a common methodological approach to study the spatial structures and trends of different geographies is a crucial prerequisite for achieving the goals set under SDGs and the New Urban Agenda.

Die primäre Proteinstruktur von Stämmen des Tabakmosaikvirus

1969 ◽  
Vol 24 (7) ◽  
pp. 877-885 ◽  
Author(s):  
H. G. Wittmann ◽  
I. Hindennach ◽  
B. Wittmann-Liebold
Keyword(s):  
Experimental Data ◽  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Amino Acid Sequence ◽  
Spatial Structure ◽  
Amino Acid Sequences ◽  
The Other ◽  
Tryptic Peptides ◽  
Tmv Strains

Experimental data for determining a) the amino acid sequences of eight tryptic peptides containing 95 amino acids and b) the order of the tryptic peptides are given. Combining the data of this and of a previous paper the complete amino acid sequence of the coat protein of the TMV strain Holmes rib grass (HRG) is established (Fig. 5). It is compared with three other TMV strains the sequences of which have been determined before (Fig. 6).Differences and similarities between the sequences of the four TMV strains are discussed. HRG has a deletion of two amino acids and it is the most distantly related of the four TMV strains. When the sequence of HRG is compared to that of any of the other strains it turns out that in each case more than 50% of the 156 positions contain different amino acids (Fig. 7).The number of positions with the same amino acid in all strains and mutants so far studied is 30 per cent. These positions are not randomly distributed but clustered mainly in two regions. This finding probably reflects the restriction of amino acid exchanges by the spatial structure of the viral rod.

Intracellular free amino acid patterns in duodenal and colonic mucosa

1990 ◽  
Vol 36 (2) ◽  
pp. 378-381 ◽  
Author(s):  
G Ollenschläger ◽  
K Langer ◽  
H M Steffen ◽  
M Schrappe-Bächer ◽  
H Schmitt ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Dry Weight ◽  
Essential Amino Acids ◽  
Medical Patients ◽  
The Mean ◽  
First Time ◽  
Duodenal Biopsies ◽  
Hiv Negative

Abstract We report for the first time the concentrations of free amino acids in human intestinal biopsies obtained by routinely performed endoscopy. We studied 15 medical patients with no changes of the mucosa and six HIV-infected persons with duodenitis. The mean (and SD) sum of all amino acids, taurine excepted, was 61.9 (5.4) mmol/kg dry weight in duodenal biopsies of HIV-negative subjects (n = 11) and 82.9 (0.6) mmol/kg in colonic specimens: 50% (44%) of the total (minus taurine) consisted of aspartate and glutamate and 14% (12%), of the essential amino acids. The relative amino acid pattern in duodenum and colon differed completely from that for muscle: aspartate was fourfold higher; glutamate, phenylalanine, glycine, valine, leucine, and isoleucine were about twofold higher. In contrast, glutamine amounted only to 4% (duodenum) to 14% (colon) of muscle glutamine. In duodenal biopsies of the HIV-infected persons, we found significantly (P less than 0.01, except glutamine: P less than 0.025) increased concentrations of glutamate (24.1 vs 17 mmol/kg dry weight), ornithine (1.4 vs 0.4), valine (2.2 vs 1.7), and glutamine.

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.

SYNTHESIS OF A NEW α-AMINO ACID, S-METHYL-β,β-DIMETHYLCYSTEINE

1946 ◽  
Vol 24b (1) ◽  
pp. 28-36 ◽  
Author(s):  
Kenneth Savard ◽  
Edwin M. Richardson ◽  
Gordon A. Grant
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Ethyl Ester ◽  
Ester Hydrochloride ◽  
First Time

A new sulphur-containing α-amino acid, S-methyl-β,β-dimethylcysteine has been prepared from S-benzyl-β,β-dimethylcysteine. These two compounds and the intermediate β,β-dimethylcysteine may be of physiological importance.S-Benzyl-β,β-dimethylcysteine has been prepared by the addition of benzyl mercaptan to α-benzoylamino-β,β-dimethylacrylic acid, its azlactone, and methyl ester, followed by hydrolysis.In addition to the above three new sulphur-containing α-amino acids, the following compounds are described, as far as the authors are aware, for the first time: methyl α-benzoylamino-β,β-dimethylacrylate, S-benzyl-N-benzoyl-β,β-dimethylcysteine and its methyl ester, the hydantoin of S-benzyl-β,β-dimethylcysteine, and S-benzyl-β,β-dimethylcysteine ethyl ester hydrochloride, and helianthate.

Urinary Amino Acid and Peptide Excretion Patterns in Patients with Muscular Dystrophy (Duchenne): A Preliminary Study with the AutoAnalyzer

1969 ◽  
Vol 15 (7) ◽  
pp. 545-554 ◽  
Author(s):  
Milton L Maskaleris ◽  
Stanislaw Gross ◽  
Ade T Milhorat
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscular Dystrophy ◽  
Urinary Amino Acids ◽  
Male Patients ◽  
Preliminary Study ◽  
Urinary Amino ◽  
First Time ◽  
Peptide Fractions ◽  
Urine Specimens

Abstract An amino acid AutoAnalyzer was used to monitor the excretion patterns of the urinary amino acids and peptides of 7 male patients (aged 3-17) with muscular dystrophy of the Duchenne type. In comparison with the output of 8 healthy boys (aged 3-12), on the average, a reduction in the excretion of Thr, Ser, Gly, Ala, Val, Ile, Tyr, Lys, and His over a 24-hr period was found in the urine of the patients, although the number of analyses was too small for statistically significant conclusions. The content of Asp, Glu, Phe, and Leu was about equal, and Pro and Hyp were present in very small quantities. Also, for the first time, a peptide analyzer was used to study the bound components from urine specimens of the patients. Excretion patterns of several peptides in three of the above patients aged 3-17 were found to differ from those of the controls. Of the six major peptide fractions examined, five were present in smaller amounts in the urine of patients; only one was elevated. It appears from these preliminary results that further study of the excretion patterns of amino acids and peptides of dystrophic patients is worthwhile, and that study of the peptides should be given preference.

Sign in / Sign up

Export Citation Format

Share Document