scholarly journals DNA Synthesis in Relation to Hyphal Branching and Wall Composition in Allomyces macrogynus

1985 ◽  
Vol 38 (1) ◽  
pp. 67 ◽  
Author(s):  
Jean Youatt
Keyword(s):  
Dna Synthesis ◽  
Sodium Sulfide ◽  
Methionine Sulfoxide ◽  
Cylindrical Shape ◽  
Sulfur Amino Acids ◽  
Hyphal Branching ◽  
The Third ◽  
Methionine Sulfone ◽  
Allomyces Macrogynus ◽  
Hyphal Tip

In A. macrogynus the first replication of DNA occurred after germination, at the time of the first branching of rhizoids. Before the second replication galactan in the wall exceeded the glucan content and was not firmly attached. After the second DNA replication hyphallengthening commenced with an increase in the content of glucan but the walls lacked rigidity. At the time of the third replication walls underwent a change which commenced at the hyphal tip and worked back to the rhizoids, converting the hyphae to a rigid, cylindrical shape. Branching commenced after the fourth replication of DNA. Multiple branching occurred when mature plants were transferred to glucose-histidine-methionine solution without further DNA synthesis. Hyphal branching was used to show that A. macrogynus was able to use methionine, methionine sulfoxide, methionine sulfone, sodium sulfide, cysteine, cystathionine and homocysteine but not cystine. Thioacetamide supported growth through many subcultures showing that A. macrogynus can synthesize its sulfur amino acids.

scholarly journals Determination of Sulfur Amino Acids in Foods as Related to Bioavailability

2008 ◽  
Vol 91 (4) ◽  
pp. 907-913 ◽  
Author(s):  
Shane M Rutherfurd ◽  
Paul J Moughan
Keyword(s):  
Methionine Sulfoxide ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Acid Oxidation ◽  
Separate Determination ◽  
Sulfur Amino Acids ◽  
Methionine Sulfone ◽  
Quantitative Impact ◽  
Selection Of

Abstract During the processing of feedstuffs and foods, methionine can be oxidized to methionine sulfoxide and methionine sulfone, and cysteine can be oxidized to cysteic acid. Methionine sulfone and cysteic acid are nutritionally unavailable, but methionine sulfoxide can be utilized, at least to some degree. The degree of utilization depends on the levels of methionine, cysteine, and methionine sulfoxide in the diet, but there is no consensus in the literature on the quantitative impact of these dietary constituents on methionine sulfoxide utilization. Methionine and cysteine are most often determined after quantitative oxidation to methionine sulfone and cysteic acid, respectively, using performic acid oxidation prior to hydrolysis. However, this method may overestimate the methionine content of processed foods, as it will include any methionine sulfoxide and methionine sulfone present. A selection of analytical methods has been developed to allow the separate determination of the 3 oxidized forms of methionine, the merits of which are discussed in this review. An additional consideration for determining methionine and cysteine bioavailability is that not all dietary methionine and cysteine is digested and absorbed from the small intestine. Selected methods designed to determine the extent of digestion and absorption are discussed. Finally, a concept for a new assay for determining methionine bioavailability, which includes determining the digestibility of methionine and methionine sulfoxide as well as the utilization of methionine sulfoxide, is presented.

scholarly journals A RADIOAUTOGRAPHIC STUDY WITH H3-THYMIDINE ON ADRENAL MEDULLA NUCLEI OF RATS INTERMITTENTLY EXPOSED TO COLD

1966 ◽  
Vol 28 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Maria Pia Viola-Magni
Keyword(s):  
Cell Division ◽  
Dna Synthesis ◽  
Adrenal Medulla ◽  
Cold Exposure ◽  
Dna Content ◽  
Room Temperature ◽  
Marked Variation ◽  
Considerable Decrease ◽  
The Third

A considerable decrease (24 to 40%) of DNA content per nucleus previously observed in the adrenal medulla of rats exposed intermittently to cold is followed by restoration to normal and supranormal values. This phenomenon has now been studied by use of H3-thymidine, which was given to normal rats, to rats exposed to cold, and to animals brought to room temperature after cold exposure. In the first two conditions, no significant labeling of nuclei was observed. In the third, labeling took place clearly in the 1st 3 days. The grain counts showed that the early labeled nuclei had more grains than those labeled later, indicating differences in the rate of DNA synthesis. A statistically significant correlation was found, on the same nuclei, between amount of Feulgen dye and number of grains. It is concluded that net synthesis of DNA takes place in the phase of recovery from cold. This fact is not related to cell division, as no mitoses could ever be detected, but rather to the cold-induced loss of DNA. Clear demonstration is thus given of a marked variation in the amount of DNA per nucleus in relation to the functional conditions of adrenal medulla cells.

Incorporation of Sulfur Amino Acids by Leucocytes during Wound Healing

1962 ◽  
Vol 8 (5) ◽  
pp. 520-525 ◽  
Author(s):  
Martin B Williamson ◽  
Mary V Whalen ◽  
Harold B Haley
Keyword(s):  
Amino Acids ◽  
Wound Healing ◽  
Normal Control ◽  
Sulfur Amino Acids ◽  
The Third

Abstract The effect of wounding on the uptake of S35-labeled amino acids by leucocytes of the blood was studied. Although a significant increase in the rate of uptake of cystine was observed after wounding, there appeared to be no effect on the incorporation of methionine. The effect was most pronounced on the third day after wounding; by the seventh day, the uptake of cystine had returned almost to the normal control rate. Experiments with substances which inhibit metabolism indicated that different mechanisms are involved in the uptake of methionine and of cystine by leucocytes.

Dna-Synthesis Studied in Later Growth Cycles and in Zoosporangium Development of Allomyces macrogynus

1988 ◽  
Vol 36 (3) ◽  
pp. 321 ◽  
Author(s):  
J Youatt
Keyword(s):  
Nucleic Acid ◽  
Dna Synthesis ◽  
Culture Medium ◽  
Morphological Differentiation ◽  
Growth Cycles ◽  
Apparent Increase ◽  
Partial Inhibition ◽  
Allomyces Macrogynus ◽  
Fourth Cycle ◽  
Nucleic Acid Assays

Synchrony of duplication cycles in Allomyces macrogynus was maintained through five cycles to the end of vegetative growth. In a culture in which hyphal emergence was inhibited the fourth cycle was abnormal. No DNA synthesis occurred before septation when zoosporangia developed in culture medium. When organisms were induced to make sporangia by transfer to water there was a small apparent increase in DNA prior to but not after septation. The unavoidable extraction of wall glycopeptide poses some problems in nucleic acid assays. Partial inhibition by 10�M benomyl allowed continued growth with large rhizoids at every apex. Partial inhibition by mitomycin allowed continued growth without any further morphological differentiation.

scholarly journals Furanyl-Rhodanines Are Unattractive Drug Candidates for Development as Inhibitors of Bacterial RNA Polymerase

2010 ◽  
Vol 54 (10) ◽  
pp. 4506-4509 ◽  
Author(s):  
Katherine R. Mariner ◽  
Rachel Trowbridge ◽  
Anil K. Agarwal ◽  
Keith Miller ◽  
Alex J. O'Neill ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Rna Polymerase ◽  
Dna Synthesis ◽  
Malate Dehydrogenase ◽  
Membrane Damage ◽  
Macromolecular Synthesis ◽  
Drug Candidates ◽  
The Third ◽  
Bacterial Rna ◽  
Inhibitor Drug

ABSTRACT Previous studies suggest that furanyl-rhodanines might specifically inhibit bacterial RNA polymerase (RNAP). We further explored three compounds from this class. Although they inhibited RNAP, each compound also inhibited malate dehydrogenase and chymotrypsin. Using biosensors responsive to inhibition of macromolecular synthesis and membrane damaging assays, we concluded that in bacteria, one compound inhibited DNA synthesis and another caused membrane damage. The third rhodanine lacked antibacterial activity. We consider furanyl-rhodanines to be unattractive RNAP inhibitor drug candidates.

scholarly journals MACROMOLECULAR SYNTHESES RELATED TO THE REPRODUCTIVE CYST OF TETRAHYMENA PATULA

1973 ◽  
Vol 59 (3) ◽  
pp. 615-623 ◽  
Author(s):  
P. R. Gabe ◽  
L. E. de Bault
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Generation Time ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Tritiated Thymidine ◽  
Growth Cycle ◽  
The Third ◽  
Rna And Protein Synthesis ◽  
The Mean

Macromolecular syntheses in encysted Tetrahymena patula were studied using Feulgen fluorescence cytophotometry, autoradiography, and inhibitors of RNA and protein synthesis. Cycloheximide significantly depressed protein synthesis and D-actinomycin effectively blocked RNA synthesis. Under these conditions, the cells within the cyst were unable to divide. Both cytophotometric measurements and autoradiographic data with tritiated thymidine show that DNA synthesis does not occur during the encystment divisions. Excysted cells placed in nutrient broth medium showed a prolonged generation time after the first cell growth cycle, and by the third generation the mean DNA content per cell was almost triple that of starved excysted cells. These findings indicate that (a) the encystment divisions require RNA and protein synthesis, which are apparently effected through turnover, (b) the encystment division cycles occur in the absence of DNA synthesis, and (c) excysted cells placed in culture medium may go through more than one DNA replication per cell cycle.

Ochratoxin production by Aspergillus ochraceus as affected by methionine and structurally related compounds

1983 ◽  
Vol 29 (5) ◽  
pp. 536-540 ◽  
Author(s):  
N. Lisker ◽  
N. Paster ◽  
I. Chet
Keyword(s):  
Radial Growth ◽  
Sole Carbon Source ◽  
Synthetic Medium ◽  
Methionine Sulfoxide ◽  
Dry Weight ◽  
Aspergillus Ochraceus ◽  
Inhibitory Effects ◽  
Methionine Sulfone ◽  
Initial Ph ◽  
Related Compounds

When 10−2 M of L- or D-methionine was added to a synthetic medium containing xylose as the sole carbon source, ochratoxin production by Aspergillus ochraceus was strongly inhibited. At that concentration methionine derivatives, e.g., α-methyl-DL-methionine, DL-methionine sulfoxide, and L-methionine sulfone, did not inhibit ochratoxin production, whereas DL-methionine S-methyl sulfonium chloride (MMSC) inhibited ochratoxin production to a large extent. L-Methionine, as well as MMSC, also completely inhibited sclerotia formation, while D-methionine and DL-methionine sulfoxide caused only a partial inhibition. At lower concentrations (10−3 and 10−4 M), none of the compounds exhibited inhibitory effects. In cases where strong ochratoxin inhibition was detected, fungal radial growth or mycelial dry weight was inhibited by only 10–25%, while the initial pH of the medium dropped from ~6.5 to ~4.4–5.0. Adjustment of the initial pH of media supplemented with 10−2 ML-methionine, D-methionine, or MMSC to a pH of ~7.8 did not change the inhibitory effects on ochratoxin production in media containing L-methionine. On the other hand, sclerotia formation was restored in all three treatments.

scholarly journals Discrimination of Methionine Sulfoxide and Sulfone by Human Neutrophil Elastase

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5344
Author(s):  
Darren Leahy ◽  
Cameron Grant ◽  
Alex Jackson ◽  
Alex Duff ◽  
Nicholas Tardiota ◽  
...  
Keyword(s):  
Tissue Damage ◽  
Neutrophil Elastase ◽  
Human Neutrophil ◽  
Critical Role ◽  
Methionine Sulfoxide ◽  
Chronic Obstructive ◽  
Human Neutrophil Elastase ◽  
Obstructive Pulmonary Disease ◽  
Methionine Residue ◽  
Methionine Sulfone

Human neutrophil elastase (HNE) is a uniquely destructive serine protease with the ability to unleash a wave of proteolytic activity by destroying the inhibitors of other proteases. Although this phenomenon forms an important part of the innate immune response to invading pathogens, it is responsible for the collateral host tissue damage observed in chronic conditions such as chronic obstructive pulmonary disease (COPD), and in more acute disorders such as the lung injuries associated with COVID-19 infection. Previously, a combinatorially selected activity-based probe revealed an unexpected substrate preference for oxidised methionine, which suggests a link to oxidative pathogen clearance by neutrophils. Here we use oxidised model substrates and inhibitors to confirm this observation and to show that neutrophil elastase is specifically selective for the di-oxygenated methionine sulfone rather than the mono-oxygenated methionine sulfoxide. We also posit a critical role for ordered solvent in the mechanism of HNE discrimination between the two oxidised forms methionine residue. Preference for the sulfone form of oxidised methionine is especially significant. While both host and pathogens have the ability to reduce methionine sulfoxide back to methionine, a biological pathway to reduce methionine sulfone is not known. Taken together, these data suggest that the oxidative activity of neutrophils may create rapidly cleaved elastase “super substrates” that directly damage tissue, while initiating a cycle of neutrophil oxidation that increases elastase tissue damage and further neutrophil recruitment.

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