Tryptophanase Activity on D-Tryptophan

2004 ◽  
pp. 321-327
Author(s):  
Akihiko Shimada ◽  
Noriko Fujii ◽  
Takeshi Saito
Keyword(s):  
Tryptophanase Activity

scholarly journals Production of 3-Nitrosoindole Derivatives by Escherichia coli during Anaerobic Growth

2009 ◽  
Vol 191 (17) ◽  
pp. 5369-5376 ◽  
Author(s):  
Young-Man Kwon ◽  
Bernard Weiss
Keyword(s):  
Escherichia Coli ◽  
Nitrous Acid ◽  
Anaerobic Growth ◽  
Functional Genes ◽  
Initial Reaction ◽  
Endonuclease V ◽  
Tryptophanase Activity ◽  
K 12 ◽  
Metabolic Reduction ◽  
Dna Repair Mutants

ABSTRACT When Escherichia coli K-12 is grown anaerobically in medium containing tryptophan and sodium nitrate, it produces red compounds. The reaction requires functional genes for trytophanase (tnaA), a tryptophan permease (tnaB), and a nitrate reductase (narG), as well as a natural drop in the pH of the culture. Mass spectrometry revealed that the purified chromophores had mass/charge ratios that closely match those for indole red, indoxyl red, and an indole trimer. These compounds are known products of chemical reactions between indole and nitrous acid. They are derived from an initial reaction of 3-nitrosoindole with indole. Apparently, nitrite that is produced from the metabolic reduction of nitrate is converted in the acid medium to nitrous acid, which leads to the nitrosation of the indole that is generated by tryptophanase. An nfi (endonuclease V) mutant and a recA mutant were selectively killed during the period of chromophore production, and a uvrA strain displayed reduced growth. These effects depended on the addition of nitrate to the medium and on tryptophanase activity in the cells. Unexpectedly, the killing of a tnaA + nfi mutant was not accompanied by marked increases in mutation frequencies for several traits tested. The vulnerability of three DNA repair mutants indicates that a nitrosoindole or a derivative of a nitrosoindole produces lethal DNA damage.

scholarly journals THE EFFECT OF CARBOHYDRATES ON THE TRYPTOPHANASE ACTIVITY OF BACTERIA1

1955 ◽  
Vol 69 (5) ◽  
pp. 584-589 ◽  
Author(s):  
William L. Boyd ◽  
Herman C. Lichstein
Keyword(s):  
Tryptophanase Activity

scholarly journals Diet posttranslationally modifies the mouse gut microbial proteome to modulate renal function

Science ◽  
2020 ◽  
Vol 369 (6510) ◽  
pp. 1518-1524 ◽  
Author(s):  
Lior Lobel ◽  
Y. Grace Cao ◽  
Kathrin Fenn ◽  
Jonathan N. Glickman ◽  
Wendy S. Garrett
Keyword(s):  
Chronic Kidney Disease ◽  
Dietary Protein ◽  
Posttranslational Modification ◽  
Bacterial Production ◽  
Microbial Community Composition ◽  
Uremic Toxin ◽  
Sulfur Amino Acid ◽  
Production Of Hydrogen ◽  
Tryptophanase Activity ◽  
Underlying Mechanisms

Associations between chronic kidney disease (CKD) and the gut microbiota have been postulated, yet questions remain about the underlying mechanisms. In humans, dietary protein increases gut bacterial production of hydrogen sulfide (H2S), indole, and indoxyl sulfate. The latter are uremic toxins, and H2S has diverse physiological functions, some of which are mediated by posttranslational modification. In a mouse model of CKD, we found that a high sulfur amino acid–containing diet resulted in posttranslationally modified microbial tryptophanase activity. This reduced uremic toxin–producing activity and ameliorated progression to CKD in the mice. Thus, diet can tune microbiota function to support healthy host physiology through posttranslational modification without altering microbial community composition.

scholarly journals Biosynthesis in vitro of tryptophanase by polyribosomes from induced cultures of Escherichia coli

1971 ◽  
Vol 123 (3) ◽  
pp. 355-365 ◽  
Author(s):  
S. A. M. Khairul Bashar ◽  
J. H. Parish ◽  
Marjorie Brown
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Enzyme Synthesis ◽  
Supernatant Fraction ◽  
Amino Acid Residues ◽  
Radioactive Amino Acid ◽  
Tryptophanase Activity

1. Polyribosomes were isolated from Escherichia coli grown in media in which tryptophanase is induced and in which it is repressed. The polyribosomes from the induced bacteria had a small amount of tryptophanase activity associated with them. 2. A portion of the enzyme activity remained bound to polyribosomes during centrifuging in sucrose gradients. 3. Incubation of tryptophanase-containing polyribosomes with puromycin released enzyme activity. 4. The binding of the enzyme to the polyribosomes did not depend on the presence of DNA. 5. When the polyribosomes were incubated under conditions of protein synthesis with supernatant fraction obtained from repressed bacteria, a small but statistically significant increase in enzyme activity was produced. 6. When a radioactive amino acid was included in the incubation mixture for the tryptophanase system a radioactive protein was obtained whose chromatographic, electrophoretic and sedimentation properties were identical with those of tryptophanase. 7. The amount of incorporation was consistent with the amount of new enzyme synthesis predicted by the increase in enzyme activity. Both radioactive incorporation and increase in enzyme activity were shown to be energy-dependent and also negative controls were obtained by using zero-time incubations or polyribosomes isolated from either repressed cells or a mutant lacking the ability to produce tryptophanase. 8. The distribution of radioactive leucine in the carboxyl region of the newly labelled tryptophanase was examined by digesting the labelled protein with carboxypeptidases. It was shown that the radioactivity was more highly concentrated towards the carboxyl terminus when the incubation times for protein synthesis were shorter (implying that, with longer incubation times, longer lengths of polypeptide chain contained radioactive amino acid residues).

Isolation of an Escherichia coli strain mutant unable to form biofilm on polystyrene and to adhere to human pneumocyte cells: involvement of tryptophanase

2002 ◽  
Vol 48 (2) ◽  
pp. 132-137 ◽  
Author(s):  
P Di Martino ◽  
A Merieau ◽  
R Phillips ◽  
N Orange ◽  
C Hulen
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
A549 Cells ◽  
Coli Strain ◽  
Gene Encoding ◽  
Cell Monolayers ◽  
E Coli ◽  
Transposon Insertion ◽  
Abiotic Surfaces ◽  
Tryptophanase Activity

Escherichia coli adherence to biotic and abiotic surfaces constitutes the first step of infection by promoting colonization and biofilm formation. The aim of this study was to gain a better understanding of the relationship between E. coli adherence to different biotic surfaces and biofilm formation on abiotic surfaces. We isolated mutants defective in A549 pneumocyte cells adherence, fibronectin adherence, and biofilm formation by random transposition mutagenesis and sequential passages over A549 cell monolayers. Among the 97 mutants tested, 80 were decreased in biofilm formation, 8 were decreased in A549 cells adherence, 7 were decreased in their adherence to fibronectin, and 17 had no perturbations in either of the three phenotypes. We observed a correlation between adherence to fibronectin or A549 cells and biofilm formation, indicating that biotic adhesive factors are involved in biofilm formation by E. coli. Molecular analysis of the mutants revealed that a transposon insertion in the tnaA gene encoding for tryptophanase was associated with a decrease in both A549 cells adherence and biofilm formation by E. coli. The complementation of the tnaA mutant with plasmid-located wild-type tnaA restored the tryptophanase activity, epithelial cells adherence, and biofilm formation on polystyrene. The possible mechanism of tryptophanase involvement in E. coli adherence and biofilm formation is discussed.Key words: Escherichia coli, biofilm, adherence, A549 cells, fibronectin, tryptophanase.

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