STUDIES ON THE BIOSYNTHESIS OF PYOCYANINE

1962 ◽  
Vol 8 (1) ◽  
pp. 49-56 ◽  
Author(s):  
J. M. Ingram ◽  
A. C. Blackwood
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Oxalic Acid ◽  
Dicarboxylic Acid ◽  
Sodium Formate ◽  
Complete Medium ◽  
Tetracarboxylic Acid ◽  
Dipotassium Salt

The biosynthesis of pyocyanine, the blue phenazine pigment produced by Pseudomonas aeruginosa, was studied by the addition of radioactive substrates to a culture growing on a complete medium. The distribution of labelled carbon from radioactive substrates in the pyocyanine was examined by degrading the pigment to 1-hydroxyphenazine, quinoxaline dicarboxylic acid, quinoxaline, and pyrazine tetracarboxylic acid dipotassium salt, and thus 7 of the 13 carbons were assayed separately or in pairs.Glycerol-1,3-C14 is the principal donor of radioactivity to the pyocyanine carbon, but not all the carbon atoms tested were labeled. Alanine-U-C14 contributed carbon to pyocyanine also, but not to all carbons, and at a much lower level of efficiency than glycerol. However, with leucine-U-C14, all carbon atoms tested were labeled to a slight extent. These amino acids, when labeled specifically, and glutamate-U-C14, oxalic acid-C14, and sodium formate-C14 did not contribute significantly to pyocyanine carbon.The distribution of radioactivity from glycerol in the pyocyanine molecule suggests the pigment is formed from glycerol or a product closely related to it by the condensation of two carbon units or the condensation of four and two carbon units.

scholarly journals The amino acid sequence of cytochromes c-551 from three species of Pseudomonas

1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Mitochondrial Cytochrome ◽  
Cytochromes C ◽  
Lending Library ◽  
Single Peptide

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

Succinic, fumaric, adipic and oxalic acid cocrystals of promethazine hydrochloride

2019 ◽  
Vol 75 (2) ◽  
pp. 107-119 ◽  
Author(s):  
Gheorghe Borodi ◽  
Alexandru Turza ◽  
Oana Onija ◽  
Attila Bende
Keyword(s):  
Oxalic Acid ◽  
Dicarboxylic Acid ◽  
Density Functional ◽  
Water Solubility ◽  
Lattice Parameter ◽  
Acetonitrile Solution ◽  
Stoichiometric Ratio ◽  
Scanning Calorimetry ◽  
Equilibrium Configurations ◽  
Promethazine Hydrochloride

Novel cocrystals of promethazine hydrochloride [PTZ-Cl; systematic name: N,N-dimethyl-1-(10H-phenothiazin-10-yl)propan-2-aminium chloride] with succinic acid (PTZ-Cl-succinic, C17H21N2S+·Cl−·0.5C4H6O4), fumaric acid (PTZ-Cl-fumaric, C17H21N2S+·Cl−·0.5C4H4O4) and adipic acid (PTZ-Cl-adipic, C17H21N2S+·Cl−·0.5C6H10O4) were prepared by solvent drop grinding and slow evaporation from acetonitrile solution, along with two oxalic acid cocrystals which were prepared in tetrahydrofuran (the oxalic acid hemisolvate, PTZ-Cl-oxalic, C17H21N2S+·Cl−·0.5C2H2O4) and nitromethane (the hydrogen oxalate salt, PTZ-oxalic, C17H21N2S+·C2HO4 −). The crystal structures obtained by crystallization from tetrahydrofuran and acetonitrile include the Cl− ion in the lattice structures, while the Cl− ion is missing from the crystal structure obtained by crystallization from nitromethane (PTZ-oxalic). In order to explain the formation of the two types of supramolecular configurations with oxalic acid, the intermolecular interaction energies were calculated in the presence of the two solvents and the equilibrium configurations were determined using density functional theory (DFT). The cocrystals were studied by X-ray diffraction, IR spectroscopy and differential scanning calorimetry. Additionally, a stability test under special conditions and water solubility were also investigated. PTZ-Cl-succinic, PTZ-Cl-fumaric and PTZ-Cl-adipic crystallized having similar lattice parameter values, and showed a 2:1 PTZ-Cl to dicarboxylic acid stoichiometry. PTZ-Cl-oxalic crystallized in a 2:1 stoichiometric ratio, while the structure lacking the Cl atom belongs has a 1:1 stoichiometry. All the obtained crystals exhibit hydrogen bonds of the type PTZ...Cl...(dicarboxylic acid)...Cl...PTZ, except for PTZ-oxalic, which forms bifurcated bonds between the hydrogen oxalate and promethazinium ions, along with an infinite hydrogen-bonded chain between the hydrogen oxalate anions.

scholarly journals Negative Regulation of the Pseudomonas aeruginosa Outer Membrane Porin OprD Selective for Imipenem and Basic Amino Acids

1999 ◽  
Vol 43 (5) ◽  
pp. 1085-1090 ◽  
Author(s):  
Martina M. Ochs ◽  
Matthew P. McCusker ◽  
Manjeet Bains ◽  
Robert E. W. Hancock
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Clinical Effectiveness ◽  
Multiple Antibiotic Resistance ◽  
Outer Membranes ◽  
Basic Amino Acids ◽  
Outer Membrane Porin ◽  
Strong Homology ◽  
Imipenem Resistance

ABSTRACT Pseudomonas aeruginosa OprD is a specific porin which facilitates the uptake of basic amino acids and imipenem, a carbapenem antibiotic. Resistance to imipenem due to the loss of OprD is an important mechanism for the loss of clinical effectiveness. To investigate the negative regulatory mechanisms influencingoprD expression, a gene upstream of the coregulatedmexEF-oprN efflux operon, designated mexT, was cloned. The predicted 304-amino-acid mature MexT protein showed strong homology to LysR-type regulators. When overexpressed it induced the expression of the mexEF-oprN efflux operon while decreasing the level of expression of OprD. The use of anoprD::xylE transcriptional fusion indicated that it acted by repressing the transcription ofoprD. Salicylate, a weak aromatic acid known to reduce porin expression and induce low levels of multiple antibiotic resistance in Escherichia coli, was able to induce imipenem resistance and reduce the expression of OprD but not multiple antibiotic resistance or OprN expression in P. aeruginosa. This was also demonstrated to occur at the level of transcription. Acetyl salicylate and benzoate, but not catechol, were also able to reduce the levels of OprD in the P. aeruginosa outer membranes. These OprD-suppressing compounds increased imipenem resistance even in a mexT-overexpressing andnfxC mutant backgrounds, suggesting that such resistance is independent of the MexT repressor and that oprD is influenced by more than a single mechanism of repression.

INHIBITION OF GROWTH OF PSEUDOMONAS DENITRIFICANS BY AMINO ACIDS

1966 ◽  
Vol 12 (6) ◽  
pp. 1095-1098 ◽  
Author(s):  
Horace J. Daniels
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basal Medium ◽  
Ammonium Phosphate ◽  
Complete Medium ◽  
Mineral Salts ◽  
Culture Studies ◽  
Pseudomonas Denitrificans ◽  
Inhibition Of Growth ◽  
Amino Acid Mixtures

A large number of amino acids failed to support growth of Pseudomonas denitrificans in a basal medium composed of glucose, ammonium phosphate, and other mineral salts. Inability of an amino acid to support growth correlated well with its inhibitory action in a complete medium made up by adding L-glutamic acid to the basal medium. D-Amino acids were more toxic than the corresponding L-forms, and neutral amino acids were more toxic than acidic amino acids. Basic amino acids which were least toxic supported the best growth. The danger of the indiscriminate use of amino acid mixtures for culture studies is discussed.

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