The effect of ammonium sulfate on the solubility of amino acids in water at (298.15 and 323.15)K

Nitrates, urea, and amino acids were suitable sources of nitrogen, within a narrow range of concentrations, for perithecial development of Venturia inaequalis in a synthetic medium. Ammonium sulfate was not. The concentration of amino acid nitrogen required to inhibit the formation of perithecia varied with the amino acid. Zinc appeared to stimulate perithecial production. Amino acids differed in the nitrogen concentrations required to inhibit formation of perithecia. Perithecia developed in low concentrations of arabinose, glucose, sucrose, lactose, and maltose but did not develop in xylose, ribose, fructose, mannose, or galactose. The disaccharides were particularly suitable. Thiamine appeared to be necessary for ascospore formation.

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Effects of amino acids on Thiobacillus acidophilus. II. Threonine deaminase

Canadian Journal of Microbiology ◽

10.1139/m80-062 ◽

1980 ◽

Vol 26 (3) ◽

pp. 385-388 ◽

Cited By ~ 3

Author(s):

Gérald Proteau ◽

Marvin Silver

Keyword(s):

Amino Acids ◽

Enzyme Activity ◽

Ammonium Sulfate ◽

Active Site ◽

Binding Sites ◽

Threonine Deaminase ◽

Low Concentrations ◽

High Concentrations ◽

Thiobacillus Acidophilus ◽

Optimal Ph

Biosynthetic L-threonine deaminase was partially purified 73-fold with a 60% recovery from Thiobacillus acidophilus by ammonium sulfate fractionation and by Sepharose 6B-C1 chromatography. The optimal pH for enzyme activity was between 9.0 and 10.0 and no optimal pH shift was observed in the presence of L-isoleucine, an inhibitor. The enzyme was effectively inhibited by L-isoleucine and showed homotropic interaction only in the presence of L-isoleucine.Kinetic studies indicate that there are at least two threonine binding sites and at least two isoleucine binding sites. The Km for threonine is 2.5 × 10−3 M. The inhibition due to isoleucine is reversed by low concentrations of L-valine. L-Valine at high concentrations acts as a substrate analogue and competitively inhibits L-threonine binding at the active site; the K1 is 1.6 × 10−2 M.

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An Extracellular Protease of Streptococcus gordonii Hydrolyzes Type IV Collagen and Collagen Analogues

Infection and Immunity ◽

10.1128/iai.67.1.271-278.1999 ◽

1999 ◽

Vol 67 (1) ◽

pp. 271-278 ◽

Cited By ~ 28

Author(s):

Zaira E. Juarez ◽

Murray W. Stinson

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Ammonium Sulfate ◽

Type Iv Collagen ◽

Bacterial Endocarditis ◽

Acid Mixture ◽

Enzyme Release ◽

Streptococcus Gordonii ◽

Type Iv Collagenase ◽

Type Iv

ABSTRACT Streptococcus gordonii is a frequent cause of infective bacterial endocarditis, but its mechanisms of virulence are not well defined. In this study, streptococcal proteases were recovered from spent chemically defined medium (CDM) and fractionated by ammonium sulfate precipitation and by ion-exchange and gel filtration column chromatography. Three proteases were distinguished by their different solubilities in ammonium sulfate and their specificities for synthetic peptides. One of the enzymes cleaved collagen analogs Gly-Pro 4-methoxy-β-naphthylamide, 2-furanacryloyl-Leu-Gly-Pro-Ala (FALGPA), and p-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-Arg (pZ-peptide) and was released from the streptococci while complexed to peptidoglycan fragments. Treatment of this protease with mutanolysin reduced its 180- to 200-kDa mass to 98 kDa without loss of enzymatic activity. The purified protease cleaved bovine gelatin, human placental type IV collagen, and the Aα chain of fibrinogen but not albumin, fibronectin, laminin, or myosin. Enzyme activity was inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. Maximum production of the 98-kDa protease occurred during growth of S. gordonii CH1 in CDM containing 0.075% total amino acids at pH 7.0 with minimal aeration. Higher initial concentrations of amino acids prevented the release of the protease without reducing cell-associated enzyme levels, and the addition of an amino acid mixture to an actively secreting culture stopped further enzyme release. The purified protease was stored frozen at −20°C for several months or heated at 50°C for 10 min without loss of activity. These data indicate that S. gordonii produces an extracellular gelatinase/type IV collagenase during growth in medium containing minimal concentrations of free amino acids. Thus, the extracellular enzyme is a potential virulence factor in the amino acid-stringent, thrombotic, valvular lesions of bacterial endocarditis.

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TRANSAMINATION IN PLANTS: THE SPECIFICITY OF AN AMINOTRANSFERASE FROM MUNG BEAN

Canadian Journal of Biochemistry ◽

10.1139/o65-083 ◽

1965 ◽

Vol 43 (6) ◽

pp. 723-730 ◽

Cited By ~ 26

Author(s):

Oluf L. Gamborg

Keyword(s):

Amino Acids ◽

Ammonium Sulfate ◽

Mung Bean ◽

Deae Cellulose ◽

Phaseolus Aureus ◽

Ammonium Sulfate Precipitation ◽

Competitive Inhibitors

A study has been made of the specificity of an aminotransferase from mung bean (Phaseolus aureus Roxb.). The enzyme was purified 40- to 60-fold by using Sephadex G-50, ammonium sulfate precipitation, DEAE-cellulose, and hydroxylapatite. In the presence of pyruvate the enzyme transaminated a number of cyclic and aliphatic amino acids. Some of the better substrates were lysine, arginine, ornithine, glutamine, methionine, leucine, 4-fiuorophenyl-alanine, phenylalanine, tyrosine, tryptophan, 3,4-dihydroxyphenylalanine, and γ-phenylbutyrine. Threonine, serine, and glycine were not transaminated. Lysine, methionine, and glutamate were competitive inhibitors of the transamination of phenylalanine.

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Hygroscopicity of amino acids and their effect on the water uptake of ammonium sulfate in the mixed aerosol particles

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.139318 ◽

2020 ◽

Vol 734 ◽

pp. 139318

Author(s):

Qingwei Luo ◽

Juan Hong ◽

Hanbing Xu ◽

Shuang Han ◽

Haobo Tan ◽

...

Keyword(s):

Amino Acids ◽

Ammonium Sulfate ◽

Water Uptake ◽

Aerosol Particles

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YNB (10×) (13.4% Yeast Nitrogen Base with Ammonium Sulfate, without Amino Acids)

Cold Spring Harbor Protocols ◽

10.1101/pdb.rec105239 ◽

2021 ◽

Vol 2021 (1) ◽

pp. pdb.rec105239

Keyword(s):

Amino Acids ◽

Ammonium Sulfate ◽

Yeast Nitrogen Base ◽

Nitrogen Base

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Homochirality as the Signature of Extra-Terrestrial Life

International Astronomical Union Colloquium ◽

10.1017/s0252921100015037 ◽

1997 ◽

Vol 161 ◽

pp. 505-510

Author(s):

Alexandra J. MacDermott ◽

Laurence D. Barron ◽

Andrè Brack ◽

Thomas Buhse ◽

John R. Cronin ◽

...

Keyword(s):

Amino Acids ◽

Protein Synthesis ◽

Optical Rotation ◽

Physical Origin ◽

Natural Choice ◽

Rosetta Mission ◽

Terrestrial Life ◽

Subsurface Layers ◽

Solar System Bodies ◽

Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

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Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

International Astronomical Union Colloquium ◽

10.1017/s025292110001469x ◽

1997 ◽

Vol 161 ◽

pp. 179-187

Author(s):

Clifford N. Matthews ◽

Rose A. Pesce-Rodriguez ◽

Shirley A. Liebman

Keyword(s):

Amino Acids ◽

Solar System ◽

Hydrogen Cyanide ◽

Nitrogen Heterocycles ◽

Laboratory Studies ◽

Heterogeneous Solids ◽

The Many ◽

Comet Halley ◽

The Impact ◽

By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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