Free, proteinaceous, and humic-bound amino acids in river water containing high concentrations of aquatic humus

1981 ◽  
Vol 15 (2) ◽  
pp. 224-228 ◽  
Author(s):  
Charles R. Lytle ◽  
Edward M. Perdue
Keyword(s):  
Amino Acids ◽  
River Water ◽  
Aquatic Humus ◽  
High Concentrations

COASTAL AND ESTUARINE SEDIMENT DYNAMICS IN THE MEZEN BAY AND ESTUARIES MEZEN AND KULOY

2018 ◽  
Author(s):  
Н. Демиденко ◽  
N. Demidenko
Keyword(s):  
River Water ◽  
River Discharge ◽  
Sea Water ◽  
Sediment Dynamics ◽  
Estuarine Sediment ◽  
Sea Surface ◽  
Cross Sectional ◽  
Sand Waves ◽  
Tidal Estuaries ◽  
High Concentrations

In the Mezen bay and estuaries Mezen and Kuloy can be high concentrations of mud suspension there, involving the formation at times mobile suspensions and settled mud. Within estuaries the river water is mixed with the sea water by the action of tidal motions, by waves on the sea surface and by the river discharge forcing its way to the sea. Nearly all shallow tidal estuaries, where currents exceed about 1,0m s-1 and where sand is present, have sand waves. Sand waves have a variety of cross-sectional and plan forms.

PAPER CHROMATOGRAPHY OF COMPLEX BIOLOGICAL MATERIALS BY SOLVENT REDEVELOPMENT WITHOUT PRIOR REMOVAL OF SALTS OR PROTEINS

1960 ◽  
Vol 38 (10) ◽  
pp. 1137-1147 ◽  
Author(s):  
Arthur E. Pasieka
Keyword(s):  
Amino Acids ◽  
Paper Chromatography ◽  
Filter Paper ◽  
Complex Mixtures ◽  
Two Dimensional ◽  
One Dimensional ◽  
Equivalent Time ◽  
Biological Compounds ◽  
High Concentrations ◽  
Subsequent Staining

A solvent redeveloping technique has been devised by which amino acids, peptides, and sugars can be separated from complex mixtures in the presence of high concentrations of salts and proteins. The separations are effected by two to four successive 18-hour solvent developments with drying between each 18-hour period before subsequent staining of the chromatograms. Better separations and resolutions are obtained by such successive 18-hour solvent developments than by one continuous solvent development for an equivalent time. The effect of these redevelopments on the separations and resolutions of biological compounds is illustrated at various stages by photographs of one- and two-dimensional chromatograms. The redevelopment technique requires filter paper sheets up to 4 ft in length for one-dimensional analytical and preparative types of chromatograms.

Quantitative Changes in Plasma Amino Acids Induced by Oral Contraceptives

1971 ◽  
Vol 41 (4) ◽  
pp. 301-307 ◽  
Author(s):  
I. L. Craft ◽  
T. J. Peters
Keyword(s):  
Amino Acids ◽  
Oral Contraceptives ◽  
Plasma Concentrations ◽  
Plasma Amino Acids ◽  
Total Plasma ◽  
Hormone Production ◽  
Contraceptive Pills ◽  
High Concentrations ◽  
Normal Women ◽  
Quantitative Changes

1. Plasma amino acids have been determined in healthy untreated women and in those receiving synthetic steroids to suppress ovulation. Both groups were studied early in the cycle when endogenous sex hormone production is low, and again later in the same cycle, when endogenous or exogenous hormones are at high concentrations respectively. 2. In normal women there is a significant decrease in plasma concentrations of serine, glutamate and ornithine, and of total amino acids in the second half of the cycle. 3. At this time those taking oral contraceptives have significant decreases in plasma concentrations of proline, glycine, alanine, valine, leucine and tyrosine, and of total plasma amino acids. In addition plasma glutamate, glycine, isoleucine and tyrosine concentrations are significantly lower than in normal women. 4. In the interval between completing one course of contraceptive pills and commencing the next, total plasma amino acid concentration reverts to normal, but a significant decrease in plasma glycine concentration persists. 5. It is suggested that these changes are due to the influence of endogenous and exogenous sex hormones respectively.

FURTHER STUDIES ON THE DUAL REQUIREMENT FOR PHENYLALANINE AND TYROSINE IN TISSUE CULTURE

1961 ◽  
Vol 39 (5) ◽  
pp. 925-932 ◽  
Author(s):  
Helen J. Morton ◽  
Joseph F. Morgan
Keyword(s):  
Amino Acids ◽  
Tissue Culture ◽  
Chick Embryo ◽  
Heart Cells ◽  
Present System ◽  
Chick Heart ◽  
High Concentrations ◽  
Chick Embryo Heart ◽  
Embryo Heart ◽  
Related Compounds

Seventeen structurally related compounds were tested for their ability to substitute for phenylalanine or tyrosine in the nutrition of chick embryo heart fragments. DL-Alanyl-DL-phenylalanine replaced phenylalanine. All other compounds had negligible effects, and most were toxic at high concentrations. β-Phenylserine, a phenylalanine antagonist, actually prolonged the survival of chick heart cells but only if both phenylalanine and tyrosine were present. Similarly, optimal reversal of β-phenylserine toxicity was dependent on the presence of both amino acids. Although phenylalanine and tyrosine are not interconvertible in the present system, it has been shown that three phenylalanine antagonists, p-fluorophenylalanine, β-2-thienylalanine, and β-phenylserine, can be identified by their relationship to tyrosine, rather than to phenylalanine.

Le transport de la phénylalanine et de la tyrosine chez Brevibacterium linens : spécificité et incorporation dans les protéines

1984 ◽  
Vol 30 (4) ◽  
pp. 430-438 ◽  
Author(s):  
P. Boyaval ◽  
Evelyne Moreira ◽  
M. J. Desmazeaud
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Cellular Protein ◽  
Cellular Proteins ◽  
Resting Cells ◽  
Brevibacterium Linens ◽  
Competitive Inhibitors ◽  
High Concentrations ◽  
Cellular Protein Synthesis

The specificity of phenylalanine and tyrosine carriers was investigated using actively metabolizing cells of Brevibacterium linens. The cellular protein synthesis of resting cells was very weakly inhibited, even with high concentrations of chloramphenicol or tetracycline. The nonaromatic amino acids were weak inhibitors for these carriers, while fluorinated analogues of phenylalanine and tyrosine were very potent competitive inhibitors. In practice these analogues cannot be used to replace amino acids to evaluate transport without incorporation because they are incorporated in cellular proteins.

Effect of fertilization on free amino acid concentrations in black spruce and jack pine containerized seedlings

1987 ◽  
Vol 17 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Y. T. Kim ◽  
C. Glerum ◽  
J. Stoddart ◽  
S. J. Colombo
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Black Spruce ◽  
Jack Pine ◽  
Foliar Nitrogen ◽  
Containerized Seedlings ◽  
High Concentrations ◽  
Amino Acid Concentrations

Greenhouse-grown black spruce and jack pine container seedlings were fertilized weekly with a 20–8–20 fertilizer at four concentrations during the fall. Seedlings were sampled when 23 weeks old towards the end of the greenhouse cultural period to determine the effect of fertilization on the free amino acid concentrations. All amino acids, except tryptophan, showed significant increases in concentration with higher levels of fertilizer; the concentration of tryptophan decreased with increasing fertilizer concentration. Amino acids with the highest concentrations in black spruce were arginine, glutamic acid, and proline, while in jack pine, besides these three, aspartic acid and glutamine were also found in high concentrations. Black spruce had significantly higher amino acid concentrations than jack pine. The concentrations of certain free amino acids may be more sensitive indicators of seedling nitrogen status than total foliar nitrogen.

Osmotic adaptation of renal medullary cells during transition from chronic diuresis to antidiuresis

1993 ◽  
Vol 264 (4) ◽  
pp. F722-F729 ◽  
Author(s):  
M. Sone ◽  
G. J. Albrecht ◽  
A. Dorge ◽  
K. Thurau ◽  
F. X. Beck
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Renal Medulla ◽  
Organic Osmolytes ◽  
Osmotic Adaptation ◽  
High Concentrations ◽  
Amino Acid Contents ◽  
Tissue Contents ◽  
Abrupt Rise

The cells of the renal medulla adapt osmotically to high extracellular tonicities by high concentrations of organic osmolytes. Intracellular accumulation of these substances is, however, relatively slow. The aim of the present study was to assess the effect of an abrupt rise in extracellular tonicity on intracellular osmotically active substances after prior reduction of medullary contents of organic osmolytes by chronic diuresis. Intra- and extracellular electrolyte concentrations at the papillary tip and the tissue contents of methylamines (glycerophosphorylcholine, betaine), polyols (myo-inositol, sorbitol), and several amino acids were determined in the different kidney zones by electron microprobe analysis and high-performance liquid chromatography in control animals, in rats infused for 6 days with furosemide via osmotic minipumps, and in rats given the vasopressin analogue [deamino-Cys1,D-Arg8]vasopressin (DDAVP) after the chronic furosemide treatment. Chronic diuresis greatly reduced interstitial tonicity and inner medullary contents of methylamines and polyols and moderately reduced inner medullary amino acid contents but did not significantly affect intracellular electrolyte concentrations. When the diuretic rats were infused with DDAVP for 2 h, interstitial tonicity more than doubled and intracellular K and Cl concentrations rose by approximately 60 and 160%, while inner medullary contents of methylamines, polyols, and amino acids were not changed significantly. These data demonstrate that after effective depletion of medullary organic osmolytes by long-term diuresis, the cells of the renal papilla adapt osmotically to an abrupt increase in extracellular tonicities by elevated cell electrolyte concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptide Cyclization at High Concentration

Synlett ◽  
2020 ◽  
Vol 31 (16) ◽  
pp. 1537-1542
Author(s):  
Monika Raj ◽  
Rachel D. Wills ◽  
Victor T. Adebomi
Keyword(s):  
Amino Acids ◽  
Cyclic Peptides ◽  
High Concentration ◽  
Peptide Cyclization ◽  
Synthetic Strategy ◽  
New Methodologies ◽  
High Concentrations

The emergence of cyclic peptides as pharmaceuticals has led to an eruption of new methodologies for macrocyclization. However, the cyclization of peptides at high concentrations presents a challenge due to the production of side products like dimers and oligomers. This factor is more pronounced with the cyclization of peptides composed of fewer than seven amino acids, thus has created a need for a new synthetic strategy. Herein, we will elucidate a new chemoselective method termed ‘CyClick’ that works in an exclusively intramolecular fashion preventing the formation of commonly occurring side products such as dimers and oligomers, even at relatively high concentration.1 Introduction2 Known Methodologies3 Novel CyClick Chemistry4 Conclusion and Outlook

scholarly journals Prebiotic amino acids bind to and stabilize prebiotic fatty acid membranes

2019 ◽  
Vol 116 (35) ◽  
pp. 17239-17244 ◽  
Author(s):  
Caitlin E. Cornell ◽  
Roy A. Black ◽  
Mengjun Xue ◽  
Helen E. Litz ◽  
Andrew Ramsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acid ◽  
Divalent Cations ◽  
Building Blocks ◽  
Rna Catalysis ◽  
Membrane Stabilization ◽  
Molecular Building Blocks ◽  
Prebiotic Amino Acids ◽  
Self Assembled ◽  
High Concentrations

The membranes of the first protocells on the early Earth were likely self-assembled from fatty acids. A major challenge in understanding how protocells could have arisen and withstood changes in their environment is that fatty acid membranes are unstable in solutions containing high concentrations of salt (such as would have been prevalent in early oceans) or divalent cations (which would have been required for RNA catalysis). To test whether the inclusion of amino acids addresses this problem, we coupled direct techniques of cryoelectron microscopy and fluorescence microscopy with techniques of NMR spectroscopy, centrifuge filtration assays, and turbidity measurements. We find that a set of unmodified, prebiotic amino acids binds to prebiotic fatty acid membranes and that a subset stabilizes membranes in the presence of salt and Mg2+. Furthermore, we find that final concentrations of the amino acids need not be high to cause these effects; membrane stabilization persists after dilution as would have occurred during the rehydration of dried or partially dried pools. In addition to providing a means to stabilize protocell membranes, our results address the challenge of explaining how proteins could have become colocalized with membranes. Amino acids are the building blocks of proteins, and our results are consistent with a positive feedback loop in which amino acids bound to self-assembled fatty acid membranes, resulting in membrane stabilization and leading to more binding in turn. High local concentrations of molecular building blocks at the surface of fatty acid membranes may have aided the eventual formation of proteins.

A TECHNIQUE OF PREPARATIVE PAPER CHROMATOGRAPHY

1966 ◽  
Vol 44 (2) ◽  
pp. 149-153 ◽  
Author(s):  
A. E. Pasieka ◽  
J. E. Logan
Keyword(s):  
Amino Acids ◽  
Paper Chromatography ◽  
Filter Paper ◽  
Biological Materials ◽  
High Salt ◽  
Salt Medium ◽  
Preparative Scale ◽  
High Concentrations ◽  
Total Amino Acids

The use of a solvent redevelopment technique enables the separation of amino acids from complex biological materials in the presence of high concentrations of salts. By conventional chromatography, 1.17 mg of total amino acids have been separated from the high salt medium M 150. The preparative technique as described here has separated amounts as great as 1.17 g and the patterns are essentially the same as for the analytical types. The separations are effected by four or more successive 15- to 20-hour solvent developments with drying between each solvent stage before the staining of chromatograms or isolation of particular bands. The results of these solvent developments on the preparative scale are illustrated with photographs of actual chromatograms. This technique requires thick filter paper sheets up to 4 ft in length for analytical, and particularly for preparative, chromatograms.

Sign in / Sign up

Export Citation Format

Share Document