scholarly journals The metabolism of 2-furoic acid by Pseudomonas F2

1969 ◽  
Vol 113 (4) ◽  
pp. 577-587 ◽  
Author(s):  
P W Trudgill

1. Pseudomonas F2 isolated by enrichment culture on 2-furoic acid and grown with it as carbon source oxidized the compound with a Qo2 of 170μl./mg. dry wt./hr. and the overall consumption of 2·5μmoles of oxygen/μmole of substrate. 2. In the presence of 1mm-sodium arsenite, oxygen uptake was restricted to 0·54μmole/μmole of 2-furoate oxidized, with the formation of 0·86μmole of 2-oxoglutarate/μmole of 2-furoate. 3. Cell suspensions, disrupted in a French pressure cell and centrifuged at 27000g, yielded supernatants capable of catalysing the slow oxidation of 2-furoate (0·17μmole/mg. of protein/hr.). 4. Fractionation of 27000g supernatants at 200000g yielded a soluble enzyme fraction capable of catalysing the oxidation of 2-furoate only in the presence of added 200000g pellet or of Methylene Blue. 5. The 2-furoate-stimulated uptake of oxygen or the anaerobic reduction of Methylene Blue by dialysed 27000g supernatant required the addition of ATP and CoA, and the rate of oxygen uptake was further enhanced by the addition of magnesium chloride and NAD+. 6. The role of ATP and CoA in the formation of 2-furoyl-CoA was demonstrated by the accumulation of 2-furoylhydroxamic acid in the presence of hydroxylamine. 7. Dialysed 200000g supernatant, treated with Dowex 1, required the addition of ATP, CoA and Methylene Blue before it could oxidize 2-furoate to 2-oxoglutarate, which was trapped in unitary stoicheiometric yield as its phenylhydrazone. Magnesium chloride and NAD+ were not stimulatory in this system. The oxidation of 2-furoate to 2-oxoglutarate was not inhibited by substrate analogues, metal ion-chelating agents, thiol-active compounds or inhibitors of cytochrome-mediated electron transport. 8. No evidence was obtained for the intervention of 2,5-dioxovalerate as an intermediate in 2-oxoglutarate formation.

1973 ◽  
Vol 134 (2) ◽  
pp. 353-366 ◽  
Author(s):  
Roger E. Cripps

1. An organism was isolated by enrichment culture that was capable of using thiophen-2-carboxylate as sole source of carbon, energy and sulphur for growth. 2. Analysis of the cellular protein after growth of the organism on thiophen-2-[14C]carboxylate showed that only glutamate, proline and arginine were labelled. All the radioactivity in the glutamate was confined to C-1. 3. In the presence of 2.1 mm-arsenite, suspensions of the organism converted thiophen-2-[14C]carboxylate into 14C-labelled 2-oxoglutarate which had the same specific radioactivity as the starting material. 4. Cell-free extracts of the organism catalysed the release of 14CO2 from thiophen-2-[14C]carboxylate. This activity was largely dependent on the presence of ATP and CoA and was stimulated by NAD+ and Mg2+. Inclusion of hydroxylamine resulted in the appearance of thiophen-2-carbohydroxamic acid, indicating that the ATP and CoA were involved in the formation of the CoA ester of thiophen-2-carboxylate. 5. High-speed centrifuging of cell-free extracts resulted in supernatants with decreased thiophen-2-carboxylate-degrading activity. Activity was restored by the addition of the high-speed pellet or by Methylene Blue. 6. The metabolism of the CoA ester of thiophen-2-carboxylate by cell-free extracts could be linked to the anaerobic reduction of Methylene Blue. 7. The sulphur atom of the thiophen nucleus was converted into sulphate by growing cultures and resting suspensions of the organism. 8. A degradative pathway is proposed involving the hydroxylation (at C-5) of the CoA ester of thiophen-2-carboxylate followed by further metabolism to 2-oxoglutarate and sulphate.


2014 ◽  
Vol 62 (S 01) ◽  
Author(s):  
I. Kanzler ◽  
F. Guo ◽  
N. Bogert ◽  
A. Moritz ◽  
A. Beiras-Fernandez

2018 ◽  
Vol 8 (1) ◽  
pp. 62 ◽  
Author(s):  
Julianna Maria Santos ◽  
Fazle Hussain

Background: Reduced levels of magnesium can cause several diseases and increase cancer risk. Motivated by magnesium chloride’s (MgCl2) non-toxicity, physiological importance, and beneficial clinical applications, we studied its action mechanism and possible mechanical, molecular, and physiological effects in prostate cancer with different metastatic potentials.Methods: We examined the effects of MgCl2, after 24 and 48 hours, on apoptosis, cell migration, expression of epithelial mesenchymal transition (EMT) markers, and V-H+-ATPase, myosin II (NMII) and the transcription factor NF Kappa B (NFkB) expressions.Results: MgCl2 induces apoptosis, and significantly decreases migration speed in cancer cells with different metastatic potentials.  MgCl2 reduces the expression of V-H+-ATPase and myosin II that facilitates invasion and metastasis, suppresses the expression of vimentin and increases expression of E-cadherin, suggesting a role of MgCl2 in reversing the EMT. MgCl2 also significantly increases the chromatin condensation and decreases NFkB expression.Conclusions: These results suggest a promising preventive and therapeutic role of MgCl2 for prostate cancer. Further studies should explore extending MgCl2 therapy to in vivo studies and other cancer types.Keywords: Magnesium chloride, prostate cancer, migration speed, V-H+-ATPase, and EMT.


Author(s):  
Stephanie Probst ◽  
Johannes Fels ◽  
Bettina Scharner ◽  
Natascha A. Wolff ◽  
Eleni Roussa ◽  
...  

AbstractThe liver hormone hepcidin regulates systemic iron homeostasis. Hepcidin is also expressed by the kidney, but exclusively in distal nephron segments. Several studies suggest hepcidin protects against kidney damage involving Fe2+ overload. The nephrotoxic non-essential metal ion Cd2+ can displace Fe2+ from cellular biomolecules, causing oxidative stress and cell death. The role of hepcidin in Fe2+ and Cd2+ toxicity was assessed in mouse renal cortical [mCCD(cl.1)] and inner medullary [mIMCD3] collecting duct cell lines. Cells were exposed to equipotent Cd2+ (0.5–5 μmol/l) and/or Fe2+ (50–100 μmol/l) for 4–24 h. Hepcidin (Hamp1) was transiently silenced by RNAi or overexpressed by plasmid transfection. Hepcidin or catalase expression were evaluated by RT-PCR, qPCR, immunoblotting or immunofluorescence microscopy, and cell fate by MTT, apoptosis and necrosis assays. Reactive oxygen species (ROS) were detected using CellROX™ Green and catalase activity by fluorometry. Hepcidin upregulation protected against Fe2+-induced mIMCD3 cell death by increasing catalase activity and reducing ROS, but exacerbated Cd2+-induced catalase dysfunction, increasing ROS and cell death. Opposite effects were observed with Hamp1 siRNA. Similar to Hamp1 silencing, increased intracellular Fe2+ prevented Cd2+ damage, ROS formation and catalase disruption whereas chelation of intracellular Fe2+ with desferrioxamine augmented Cd2+ damage, corresponding to hepcidin upregulation. Comparable effects were observed in mCCD(cl.1) cells, indicating equivalent functions of renal hepcidin in different collecting duct segments. In conclusion, hepcidin likely binds Fe2+, but not Cd2+. Because Fe2+ and Cd2+ compete for functional binding sites in proteins, hepcidin affects their free metal ion pools and differentially impacts downstream processes and cell fate.


2003 ◽  
Vol 100 (10) ◽  
pp. 5670-5675 ◽  
Author(s):  
D. Mustafi ◽  
A. Bekesi ◽  
B. G. Vertessy ◽  
M. W. Makinen
Keyword(s):  

2004 ◽  
Vol 116 (28) ◽  
pp. 3814-3817 ◽  
Author(s):  
Anne Bleuzen ◽  
Virginie Escax ◽  
Alban Ferrier ◽  
Françoise Villain ◽  
Michel Verdaguer ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document