l-Azaserine as an inducing agent for the development of phage in the lysogenic Escherichia coli, K-12

Gots, Joseph S.; Bird, Thomas J.; Mudd, Stuart

doi:10.1016/0006-3002(55)90401-7

Cited by 26 publications

(7 citation statements)

References 4 publications

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“…A simple assay system for monitoring and investigating this dietary effect would be useful, so we investigated the action of azaserine, as influenced by the presence of rat tissue extract, in a bacterial assay: induction of lambda (A) bacteriophage in lysogenic Escherichia coli. Azaserine can cause bacteriophage induction and mutation in bacteria without prior activation by mammalian enzymes [Gots et al, 1955;McCann et al, 1975;Staiano et al, 19801, but we found that rat tissue extracts markedly enhanced induction by azaserine. Hepatic extracts from lipotrope-deficient rats were somewhat more active than extracts from normal rats.…”

Section: Introductionmentioning

confidence: 69%

Enhancing activity of rat tissue extracts for induction of lambda prophage by L‐azaserine

et al. 1984

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We studied the effect of rat tissue extracts on induction of lambda prophage in Escherichia coli (lambda) by L-azaserine. Hepatic and pancreatic extracts, primarily the cytosolic fraction, markedly increased the rate of induction. Hepatic extracts from lipotrope-deficient rats were somewhat more active than extracts from normal rats. The enhancing activity in normal rat hepatic cytosol was partially characterized. It reduced by about one-half the dose of azaserine required for a given purpose. The enhancement was increased by preincubating the bacterial cells with cytosol; cells retained the effect after cytosol was removed. Enhancing activity was inhibited strongly by the amino acids phenylalanine, tryptophan, and tyrosine; to lesser extents by leucine, methionine, and serine; and not at all by proline or glutamine. It was eliminated by dialysis of the cytosol and reduced by omission of nicotinamide adenine dinucleotide phosphate (NADP) from the reaction mixture. Heating the cytosol to 60 degrees C or 80 degrees C or varying the pH of the reaction mixture from 6 to 8 had no significant effect. Treating the cytosol with trypsin appeared to release an inhibitor of the activity. Glutathione, cysteine, and beta-mercaptoethanol also enhanced lambda induction by azaserine, but the cytosolic activity was not affected by the thiol-inactivating compound diethylmaleate (DEM). The results suggest that factors in cytosol interact with bacterial cells to facilitate transport of azaserine into the cells, primarily through the aromatic amino acid transport system. A small molecule, not a free thiol compound, appears to be involved. It may serve to establish reducing conditions protective for azaserine, the probable mechanism of action of sulfhydryl compounds.

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Section: Introductionmentioning

confidence: 69%

Enhancing activity of rat tissue extracts for induction of lambda prophage by L‐azaserine

et al. 1984

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“…It is possible that the ML35 lysate contains only a defective phage, which could not be detected by conventional means. Because of the work of Gots et al (1955) it seems simpler to assume the lysis induced by azaserine is due to an event related to lysogenicity rather than to some other cause.…”

Section: Resultsmentioning

confidence: 99%

Reversal of Azaserine by Phenylalanine

Brock

1961

J Bacteriol

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Kaplan, Reilly, and Stock (1959) have studied the reversal of azaserine by aromatic amino acids and have hypothesized without any direct evidence that these substances prevent the binding or penetration of the antibiotic into the cell. The present paper presents more direct evidence that this hypothesis is correct. It is shown that azaserine acts on nongrowing cells of Escherichia coli strain ML35 in such a way that subsequent growth in azaserine-free medium leads to increases in permeability, lysis, and death. It has been found that phenylalanine reverses only when it is present during the azaserine treatment and has no effect when present during the subsequent growth period. These results are interpreted to mean that phenylalanine prevents the binding or penetration of azaserine into the cell, but plays no direct role in preventing the metabolic disarrangements caused by azaserine. This work has been aided by a strain (ML35) of E. coli which forms 0-galactosidase constitutively at high levels but lacks a permease. This strain is useful in detecting nonspecific effects on permeability.

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“…This induction ability attributed to a particular substance has been related to carcinogenic, carcinostatic, or mutagenic properties of the agent (1, 7, 9-10, 15, 25, 30-31). Several reports have described procedures involving production of infective phage from lysogenic bacteria as a screening mechanism for compounds that cause tumors, mutations, or are tumoricidal (8,11,14,19,27). Mechanism studies of inducing substances have shown that they have in common the characteristic of inhibiting host cell deoxyribonucleic acid (DNA) metabolism (20)(21)26).…”

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confidence: 99%

Aflatoxin B1 Induction of Lysogenic Bacteria

Lillehoj

Ciegler

1970

Applied Microbiology

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A technique for biological verification of aflatoxin B1 was developed based on toxin-mediated induction of lysis in a lysogenic strain of Bacillus megateriun NNRL B-3695. Reduction of culture turbidity was determined at various concentrations of toxin. Incubation of 1.1 X 10-4 g (dry weight) of cells/ml of growth medium containing 25 ,ug of B, per ml at 37 C reduced initial turbidity 0.20 absorbance units in 4 hr. If the bacterial lysate of the lysogenic strain, after a 2-hr incubation with 25 ,ug of B1 per ml, was plated with a sensitive B. megaterium strain (NRRL B-3694), plaque-forming units increased approximately 150 times relative to the control. Comparable testing of the effects of aflatoxin on the nonlysogenic, sensitive strain demonstrated that 75 ,ug of B1 per ml neither induced lysis nor plaque-forming units. Although induction is not an exclusive property of aflatoxin B1, the differential response of the lysogenic and sensitive Bacillus strains to B1 offers a unique and rapid technique for biological verification of the toxin.

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l-Azaserine as an inducing agent for the development of phage in the lysogenic Escherichia coli, K-12

Cited by 26 publications

References 4 publications

Enhancing activity of rat tissue extracts for induction of lambda prophage by L‐azaserine

Enhancing activity of rat tissue extracts for induction of lambda prophage by L‐azaserine

Reversal of Azaserine by Phenylalanine

Aflatoxin B1 Induction of Lysogenic Bacteria

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