A new antibiotic, fumaramidmycin I. Production, biological properties and characterization of producer strain.
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A new antibiotic, fumaramidmycin, has been isolated from a streptomycete NR-7GG1 which was characterized and named Streptomyces kurssanovii. The strain produced the antibiotic only when grown on agar plates but not in the submerged culture broth, where the contact with the vegetative mycelia appears to cause the inactivation of the antibiotic. The antibiotic shows an antimicrobial activity against both Gram-positive and Gram-negative bacteria. (+info)
A new antibiotic, fumaramidmycin. II. Isolation, structure and syntheses.
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A new antibiotic fumaramidmycin produced by Streptomyces kurssanovii NR-7GG1 was isolated as colorless crystals. The structure was shown to be N-(phenylacetyl) fumaramide. Starting from fumaramic acid, fumaramidmycin has been synthesized in good yield, in which the key stage involves N-acylated imino ether formation followed by mild acid hydrolysis. Five analogues of fumaramidmycin have also been prepared. (+info)
Dimethylfumarate inhibits tumor-necrosis-factor-induced CD62E expression in an NF-kappa B-dependent manner.
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Fumaric acid esters are thought to improve psoriasis by altering leukocyte, keratinocyte, and/or endothelial functions. To determine specificity, kinetics, and molecular mechanisms of different fumaric acid esters in their ability to inhibit endothelial cell activation, we analyzed CD62E and CD54 expression in endothelial cells in vivo and in vitro. In lesional skin of psoriatic patients, oral fumaric acid ester treatment resulted in a marked reduction of CD62E but not CD54 expression on dermal microvessels. Using human umbilical vein endothelial cells, dimethylfumarate almost completely inhibited tumor-necrosis-factor-induced CD62E, but not CD54 expression at concentrations < or = 70 microM, mimicking the situation in vivo. A 60 min dimethylfumarate preincubation was sufficient to block tumor-necrosis-factor-induced CD62E expression for up to 24 h. In contrast, equimolar concentrations of methylhydrogenfumarate, the hydrolysis product of dimethylfumarate, did not suppress tumor-necrosis-factor-induced CD62E expression. Likewise, all fumaric acid esters other than dimethylfumarate were ineffective. Using CD62E, NF-kappa B, or AP-1-responsive promoter constructs, dimethylfumarate inhibited tumor-necrosis-factor-induced activation of the CD62E and the NF-kappa B but not the AP-1 promoter construct. In summary, at a dose range < or = 70 microM, dimethylfumarate appeared to be a specific inhibitor of CD62E expression in an NF-kappa B-dependent manner. (+info)
Treatment of disseminated granuloma annulare with fumaric acid esters.
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BACKGROUND: Granuloma annulare is a granulomatous disease of unknown etiology. Various therapies have been tried in disseminated granuloma annulare (DGA), including corticosteroids, several variants of psoralen plus ultraviolet-A radiation, ultraviolet- A1 radiation, systemic retinoids, and dapsone, with variable success. We report a patient with recalcitrant DGA who was treated with fumaric acid esters (FAE). CASE PRESENTATION: A 40-year old Caucasian woman presented with a 25-year history of recalcitrant DGA. On both legs and the abdomen there were erythematous annular plaques. She was treated with FAE in tablet form using two formulations differing in strength (low strength tablets: 30 mg dimethylfumarate, 67 mg monoethylfumarate Ca salt, 5 mg monoethylfumarate Mg salt, 3 mg monoethylfumarate Zn salt; high strength tablets: 120 mg dimethylfumarate, 87 mg monoethylfumarate Ca salt, 5 mg monoethylfumarate Mg salt, 3 mg monoethylfumarate Zn salt). After three-month therapy, an almost complete clearance of skin lesions was achieved. With the exception of temporary lymphopenia, no adverse effects were observed. The patient remained in remission during a six-month follow up period. CONCLUSIONS: Our observation has demonstrated that FAE is a potentially beneficial therapeutic option for patients with recalcitrant DGA. However controlled trials are necessary to fully explore the efficacy, optimal dosage, and safety of FAE in the management of DGA. (+info)
Keto acid metabolism in Desulfovibrio.
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Four strains of Desulfovibrio each excreted pyruvate to a constant level during growth; it was re-absorbed when the substrate (lactate) was exhausted. Malate, succinate, fumarate and malonate also accumulated during growth. One of the strains (Hildenborough) excreted alpha-ketoglutarate as well as pyruvate when incubated in nitrogen-free medium; the former was re-absorbed on addition of NH4Cl. In a low-lactate nitrogen-free medium, strain Hildenborough rapidly re-absorbed the pyruvate initially excreted, but did not re-absorb the alpha-ketoglutarate. Arsenite (I mM) prevented the accumulation of alpha-ketoglutarate; I mM-malonate did not affect the accumulation of keto acids. Isocitrate dehydrogenase activity (NAD-specific) in all strains was lower than NADP-specific glutamate dehydrogenase activity. Alpha-Ketoglutarate dehydrogenase could not be detected in any strain. NADPH oxidase activity was demonstrated. This and previous work indicate that a tricarboxylic acid pathway from citrate to alpha-ketoglutarate exists in Desulfovibrio spp., and that succinate can be synthesized via malate and fumarate; however, an intact tricarboxylic acid cycle is evidently not present. The findings are compared with observations on biosynthetic pathways in clostridia, obligate lithotrophs, phototrophs, and methylotrophs, and various facultative bacteria. (+info)
Reconstitution of coupled fumarate respiration in liposomes by incorporating the electron transport enzymes isolated from Wolinella succinogenes.
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Hydrogenase and fumarate reductase isolated from Wolinella succinogenes were incorporated into liposomes containing menaquinone. The two enzymes were found to be oriented solely to the outside of the resulting proteoliposomes. The proteoliposomes catalyzed fumarate reduction by H2 which generated an electrical proton potential (Delta(psi) = 0.19 V, negative inside) in the same direction as that generated by fumarate respiration in cells of W. succinogenes. The H+/e ratio brought about by fumarate reduction with H2 in proteoliposomes in the presence of valinomycin and external K+ was approximately 1. The same Delta(psi) and H+/e ratio was associated with the reduction of 2,3-dimethyl-1,4-naphthoquinone (DMN) by H2 in proteoliposomes containing menaquinone and hydrogenase with or without fumarate reductase. Proteoliposomes containing menaquinone and fumarate reductase with or without hydrogenase catalyzed fumarate reduction by DMNH2 which did not generate a Delta(psi). Incorporation of formate dehydrogenase together with fumarate reductase and menaquinone resulted in proteoliposomes catalyzing the reduction of fumarate or DMN by formate. Both reactions generated a Delta(psi) of 0.13 V (negative inside). The H+/e ratio of formate oxidation by menaquinone or DMN was close to 1. The results demonstrate for the first time that coupled fumarate respiration can be restored in liposomes using the well characterized electron transport enzymes isolated from W. succinogenes. The results support the view that Delta(psi) generation is coupled to menaquinone reduction by H2 or formate, but not to menaquinol oxidation by fumarate. Delta(psi) generation is probably caused by proton uptake from the cytoplasmic side of the membrane during menaquinone reduction, and by the coupled release of protons from H2 or formate oxidation on the periplasmic side. This mechanism is supported by the properties of two hydrogenase mutants of W. succinogenes which indicate that the site of quinone reduction is close to the cytoplasmic surface of the membrane. (+info)
Dimethylfumarate inhibits TNF-induced nuclear entry of NF-kappa B/p65 in human endothelial cells.
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Fumaric acid esters, mainly dimethylfumarate (DMF), have been successfully used to treat psoriasis. Based on previous observations that DMF inhibited expression of several TNF-induced genes in endothelial cells, we wished to explore the molecular basis of DMF function in greater detail. In first experiments we analyzed DMF effects on tissue factor expression in human endothelial cells in culture, because tissue factor is expressed by two independent sets of transcription factors, by NF-kappa B via TNF and by early gene response-1 transcription factor via vascular endothelial growth factor (VEGF). We show that DMF inhibits TNF-induced tissue factor mRNA and protein expression as well as TNF-induced DNA binding of NF-kappa B proteins, but not VEGF-induced tissue factor protein, mRNA expression, or VEGF-induced early gene response-1 transcription factor/DNA binding. To determine where DMF interferes with the TNF/NF-kappa B signaling cascade, we next analyzed DMF effects on I kappa B and on the subcellular distribution of NF-kappa B. DMF does not inhibit TNF-induced I kappa B alpha phosphorylation and I kappa B degradation; thus, NF-kappa B is properly released from I kappa B complexes even in the presence of DMF. Importantly, DMF inhibits the TNF-induced nuclear entry of NF-kappa B proteins, and this effect appears selective for NF-kappa B after the release from I kappa B, because the constitutive shuttling of inactive NF-kappa B/I kappa B complexes into and out from the nucleus is not blocked by DMF. Moreover, DMF does not block NF-kappa B/DNA binding. In conclusion, DMF appears to selectively prevent the nuclear entry of activated NF-kappa B, and this may be the basis of its beneficial effect in psoriasis. (+info)
Plausible molecular mechanism for activation by fumarate and electron transfer of the dopamine beta-mono-oxygenase reaction.
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A series of fumarate analogues has been used to explore the molecular mechanism of the activation of dopamine beta-mono-oxygenase by fumarate. Mesaconic acid (MA) and trans -glutaconic acid (TGA) both activate the enzyme at low concentrations, similar to fumarate. However, unlike fumarate, TGA and MA interact effectively with the oxidized enzyme to inhibit it at concentrations of 1-5 mM. Monoethylfumarate (EFum) does not activate the enzyme, but inhibits it. In contrast with TGA and MA, however, EFum inhibits the enzyme by interacting with the reduced form. The saturated dicarboxylic acid analogues, the geometric isomer and the diamide of fumaric acid do not either activate or inhibit the enzyme. The phenylethylamine-fumarate conjugate, N -(2-phenylethyl)fumaramide (PEA-Fum), is an approximately 600-fold more potent inhibitor than EFum and behaves as a bi-substrate inhibitor for the reduced enzyme. The amide of PEA-Fum behaves similarly, but with an inhibition potency approximately 20-fold less than that of PEA-Fum. The phenylethylamine conjugates of saturated or geometric isomers of fumarate do not inhibit the enzyme. Based on these findings and on steady-state kinetic analysis, an electrostatic model involving an interaction between the amine group of the enzyme-bound substrate and a carboxylate group of fumarate is proposed to account for enzyme activation by fumarate. Furthermore, in light of the recently proposed model for the similar copper enzyme, peptidylglycine alpha-hydroxylating mono-oxygenase, the above electrostatic model suggests that fumarate may also play a role in efficient electron transfer between the active-site copper centres of dopamine beta-mono-oxygenase. (+info)