scholarly journals STUDIES IN LIVER AND KIDNEY FUNCTION IN EXPERIMENTAL PHOSPHORUS AND CHLOROFORM POISONING

1915 ◽  
Vol 22 (3) ◽  
pp. 333-346 ◽  
Author(s):  
E. K. Marshall ◽  
L. G. Rowntree
Keyword(s):  
Amino Acids ◽  
Renal Insufficiency ◽  
Amino Nitrogen ◽  
Ion Concentration ◽  
Protein Nitrogen ◽  
Hydrogen Ion Concentration ◽  
Functional Changes ◽  
Phosphorus Poisoning ◽  
Renal Changes ◽  
Liver And Kidney

1. We have confirmed the results of previous workers on tetrachlorphthalein, fibrinogen, and lipase. 2. The total non-protein nitrogen, urea, and amino-acids of the blood serum show a definite and sometimes marked increase in phosphorus poisoning. These changes are not so evident in chloroform poisoning, although they sometimes occur. They are usually terminal phenomena. 3. The urinary nitrogen partition between the urea, ammonia, and amino-acids is not always disturbed. The most important changes which occur are an increased amino nitrogen in chloroform and phosphorus poisoning, and a very low urea nitrogen percentage in severe fatal chloroform poisoning. 4. Sugar tolerance towards galactose and levulose is in general markedly decreased in both types of poisoning. 5. In phosphorus poisoning liver functional changes can and do occur without concomitant renal changes. Renal insufficiency usually arises as a terminal event. 6. Increased nitrogenous products in the blood (total non-protein nitrogen, urea, and amino nitrogen) are associated with an increase of these bodies in the urine. Consequently, an increased protein catabolism, as well as renal insufficiency, is necessary to explain this accumulation. 7. A terminal acidosis, as evidenced by increased hydrogen ion concentration in the blood, usually occurs.

Action of proteolytic enzymes on wheat gluten

1968 ◽  
Vol 46 (9) ◽  
pp. 1019-1022 ◽  
Author(s):  
Hung-Ju Yang ◽  
A. G. McCalla
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Proteolytic Enzymes ◽  
Wheat Gluten ◽  
Amino Nitrogen ◽  
Protein Nitrogen ◽  
Early Stages ◽  
Mean Size ◽  
Terminal Amino ◽  
The Mean

Papain and trypsin partially hydrolyzed wheat gluten dispersed in 10% sodium salicylate, and pepsin partially hydrolyzed gluten dispersed in aluminium lactate. Trypsin was considerably less effective than either papain or pepsin. Papain produced non-protein nitrogen most rapidly during early stages of hydrolysis but pepsin produced the largest total after 48 h. The rate of release of terminal amino nitrogen was similar for papain and pepsin, and release was not complete after 48 h. The mean size of polypeptides was larger in papain than in pepsin hydrolysates during early stages of hydrolysis but definitely smaller after 48 h. Only pepsin released appreciable amounts of free amino acid nitrogen. Leucine and phenylalanine made up over 50% of the free amino acids after 48 h but several other amino acids were found in significant quantities.

scholarly journals THE ABNORMAL COURSE OF BACTERIAL PROTEIN SYNTHESIS IN THE PRESENCE OF PENICILLIN

1950 ◽  
Vol 91 (4) ◽  
pp. 351-364 ◽  
Author(s):  
Rollin D. Hotchkiss
Keyword(s):  
Amino Acids ◽  
Amino Nitrogen ◽  
Cellular Protein ◽  
Penicillin G ◽  
Bacterial Protein ◽  
Protein Nitrogen ◽  
Amino Acid Nitrogen ◽  
Extracellular Substances ◽  
Bacterial Protein Synthesis ◽  
Peptone Broth

Washed staphylococcal cells separated from peptone-broth cultures containing penicillin G did not differ markedly from cells not exposed to penicillin in their rate of oxygen, phosphate, glutamic acid, or amino nitrogen utilization. Washed normal staphyloccal cells, respiring in solutions containing glucose and various mixtures of amino acids, utilized the amino acids with an increase in the cellular protein nitrogen. Similar cells under the same conditions, but exposed to penicillin G, utilized oxygen, phosphate, and amino acids at essentially the same rates, but there was no increase in the protein nitrogen of the cells. Penicillin-treated washed cells, when utilizing amino acids, produced increased amounts of extracellular substances containing non-amino nitrogen in quantities approximately equivalent to the amino acid nitrogen utilized. The non-amino fraction could be tentatively identified as polypeptide, which was produced, instead of cellular protein, when penicillin was present.

The Purification and Fractionation of Rubber. (7th Communication)

1929 ◽  
Vol 2 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Rudolf Pummerer ◽  
Albrecht Andriessen ◽  
Wolfgang Gündel
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Nitrogen Content ◽  
Amino Nitrogen ◽  
Prolonged Treatment ◽  
Protein Nitrogen ◽  
De Vries ◽  
Ninhydrin Reaction ◽  
Long Storage

Abstract I—The Alkali Purification of Concentrated Latex. Nitrogenous Impurities in Latex Preserved with Ammonia It has already been shown that in the purification of latex by alkali, fresh and ammonia-preserved latex behave differently toward alkali. The former is changed even in the cold through decomposition of the proteins (as shown independently by de Vries and Beumée-Nieuwland), whereas the latter first shows evidences of changes at 50°, at which point it creams. Furthermore, experiments with “Revertex”, a concentrated latex, have shown that ammonia-preserved latex is changed in a still different way. Pummerer and Pahl consider the “total rubber”, obtained by them from ammonia-preserved latex by the action of alkali, to be free proteins and nitrogen. This view is, however, open to correction. Total rubber is probably fairly free of proteins, but contains nitrogen. The nitrogen content, which is still appreciable even after prolonged treatment with alkali at 50??, varies from 0.15 to 0.4%. This nitrogen was at first overlooked, because it was not detected in a few qualitative Lassaigne tests, nor in a quantitative Dumas determination. Moreover analysis indicated nearly 100% of hydrocarbon. Nevertheless new tests have shown that many samples contained 0.4% nitrogen. When the samples were incinerated with a reduced copper spiral, there was a deficit of 0.4% in the carbon-hydrogen determinations. Accordingly a substance containing 0.4% protein-nitrogen would show a deficit of about 1% on account of the oxygen in the protein. The nitrogen remaining after the alkali purification of ammonia-preserved latex is not protein-nitrogen but amino-nitrogen, which probably is formed by the action of ammonia during long storage. A gel-rubber (0.4% nitrogen) refluxed in benzene for a day with dilute NaOH yielded no amino acids to the NaOH. The neutralized aqueous solution did not give the ninhydrin reaction, nor did the rubber itself when it was boiled with the reagent.

The Formation of 3-Phenyl-2-thiohydantoins from Phenylthiocarbamyl Amino Acids

1963 ◽  
Vol 16 (3) ◽  
pp. 411 ◽  
Author(s):  
D Ilse ◽  
P Edman
Keyword(s):  
Amino Acids ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Degradation Of Peptides

In an attempt to extend the application of the phenylisothiocyanate degradation of peptides it was found necessary to study the kinetics of the conversion of phenylthiocarbamyl amino acids into phenylthiohydantoins. The conversion was found to obey first-order kinetics and to be catalyzed by hydrogen ions. A set of conditions with regard to time, hydrogen ion concentration and temperature was found, which allowed the quantitative or near quantitative conversion of all phenylthiocarbamyl amino acids into phenylthiohydantoins with the only exception of the phenylthiohydantoin of serine, which was returned in a yield of 20%.

Effects of Nitrogen Source and Concentration on the Free Amino Acid Composition of Developing Wheat Grains

1990 ◽  
Vol 17 (2) ◽  
pp. 199 ◽  
Author(s):  
C Blumenthal ◽  
JW Lee ◽  
EWR Barlow ◽  
IL Batey
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ammonium Nitrate ◽  
Amino Acid Composition ◽  
Free Amino Acid ◽  
Acid Composition ◽  
Free Amino ◽  
Amino Nitrogen ◽  
Grain Protein ◽  
Protein Nitrogen

Detached wheat heads (7 days post-anthesis) were grown in liquid culture containing nitrogen concentrations of 0.025% or 0.1% in the form of glutamine, ammonium nitrate or asparagine. With each form of the nitrogen, increasing the concentrations of nitrogen in the culture medium led to increases in the total nitrogen and the non-protein nitrogen in the grain. Protein contents (N × 5.7) were approximately 16% and 21% on a dry weight basis in the low and high treatments respectively for all nitrogen sources. Amino acids from the endosperm cavity, the ethanol-soluble extract of the grain, and the grain protein were analysed by HPLC techniques to define the site of transfer between amino acid forms. The results indicated that amino nitrogen from glutamine, ammonium nitrate, or asparagine enters the grain and is found in the endosperm cavity fluid mainly in the form of glutamine, alanine and, to a lesser extent, aspartate (including asparagine). These amino acids are then converted into the various other amino acids required for protein synthesis, as is demonstrated by the increases found in the others in the ethanol-soluble free amino acid fraction with different nitrogen regimes. These variations in the composition of the free amino acids occurred without altering the amino acid composition of the protein component of the grain.

Stereochemical requirements for the formation of vanadate complexes with peptides

1991 ◽  
Vol 69 (10) ◽  
pp. 1600-1607 ◽  
Author(s):  
JASWINDER S. Jaswal ◽  
Alan S. Tracey
Keyword(s):  
Amino Acids ◽  
Magnetic Resonance ◽  
Weak Interactions ◽  
Chemical Shifts ◽  
Formation Constants ◽  
Product Formation ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Carboxylate Groups ◽  
Peptide Linkage

The condensation reactions occurring between vanadate and a number of amino acids and simple peptides have been studied by 51V nuclear magnetic resonance. Vanadate and ligand stoichiometry has been established for the complexes formed and their formation constants determined. The amino acids were all found to undergo rather weak interactions with vanadate and in general provided two products with 51V chemical shifts near −545 and −555 ppm. The peptides also gave minor products with NMR signals occurring with that of vanadate itself. However, in this case, the major products occur at approximately −510 ppm. These latter complexes are monovanadate, monoligand complexes which require the terminal amino, the carboxylate groups and an unsubstituted nitrogen in the peptide linkage in order for product formation to occur. Sidechains promote product formation, apparently by favouring a more readily complexed peptide conformation. Formation constants vary from about 20 to 50 M−1 depending on the sidechain. The carboxylate group can be replaced by a hydroxymethyl. This, however, leads to a significant decrease in product formation at pH 7. Hydrogen ion concentration studies showed that the complexes, when considered to be formed from VO4H2− and neutral peptide, did not require or give off protons. However, when the carboxylate was replaced by the alcohol functionality a proton was released. On the basis of this study the coordination of the vanadate/peptide complexes has been assigned. Key words: peptide, vanadate, complexes, vanadium magnetic resonance.

scholarly journals Studies in the fat metabolism of the Timothy Grass Bacillus. II.—The carbon balance-sheet and respiratory quotient

1923 ◽  
Vol 95 (666) ◽  
pp. 200-206 ◽  
Keyword(s):  
Respiratory Quotient ◽  
Synthetic Medium ◽  
Balance Sheet ◽  
Potassium Phosphate ◽  
Ammonium Phosphate ◽  
Sole Source ◽  
Ion Concentration ◽  
Protein Nitrogen ◽  
Hydrogen Ion Concentration ◽  
Timothy Grass

It was shown in a previous communication [Stephenson and Whetham, 1922 (1)] that the Timothy Grass Bacillus can be cultivated on a synthetic medium containing potassium phosphate (KH 2 PO 4 : 0·4 per cent.), and magnesium sulphate (MgSO 4 . 7H 2 O : 0·07 per cent.), with ammonium phosphate ((NH 4 ) 2 . HPO 4 : 0·4 per cent.) as the sole source of nitrogen, and glucose (1 percent.) as the sole source of carbon. The cultivation was carried out in Roux bottles, and the hydrogen ion concentration was kept constant at P H = 8·0 by the presence of excess of calcium carbonate. Under these conditions, the glucose was completely used in about 21 days; no breakdown products other than carbon dioxide were found; the protein nitrogen and lipoid contents of the bacillus were estimated at intervals and found to attain a maximum immediately before the glucose was used up; the fat of the organism then rapidly fell off, though no decrease was detected in the protein as estimated by Kjeldahl’s method. It therefore appeared that while growing in a medium containing a sufficiency of glucose, the organism stored fat, which was oxidised when the glucose was exhausted—the organism living at the expense of its fat and saving its protein. More recently, somewhat similar work on Aspergillus niger has been reported by Terroine, Wurmser and Montané [1922 (2)], who deprived the fully grown fungus of both nitrogenous and carbon-containing foodstuffs, and found a considerable fall in the percentage content of nitrogen in the organism. Kosinski [1902 (3)] had observed that the respiratory quotient of A . nigher on a glucose-containing medium is about 1, but falls off to 0·8 during starvation. This result, taken in conjunction with their own, led Terroine, Wurmser, and Montané to the conclusion that A . niger uses protein as a reserve material rather than cellulose. No particular observations seem to have been made on the fat content of A . niger . The work is not exactly comparable with ours on the Timothy Grass Bacillus, as ammonia was always present in the medium in our experiments.

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