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PubMed2002

Biochemical evidence for formate transfer in syntrophic propionate-oxidizing cocultures of Syntrophobacter fumaroxidans and Methanospirillum hungatei.

The hydrogenase and formate dehydrogenase levels in Syntrophobacter fumaroxidans and Methanospirillum hungatei were studied in syntrophic propionate-oxidizing cultures and compared to the levels in axenic cultures of both organisms. Cells grown syntrophically were separated from each other by Percoll gradient centrifugation. In S. fumaroxidans both formate dehydrogenase and hydrogenase levels were highest in cells which were grown syntrophically, while the formate-H(2) lyase activities were comparable under the conditions tested. In M. hungatei the formate dehydrogenase and formate-H(2) lyase levels were highest in cells grown syntrophically, while the hydrogenase levels in syntrophically grown cells were comparable to those in cells grown on formate. Reconstituted syntrophic cultures from axenic cultures immediately resumed syntrophic growth, and the calculated growth rates of these cultures were highest for cells which were inoculated from the axenic S. fumaroxidans cultures that exhibited the highest formate dehydrogenase activities. The results suggest that formate is the preferred electron carrier in syntrophic propionate-oxidizing cocultures of S. fumaroxidans and M. hungatei.

Biological Transport↗
PubMed1988

Regulation of carbon and electron flow in Propionispira arboris: relationship of catabolic enzyme levels to carbon substrates fermented during propionate formation via the methylmalonyl coenzyme A pathway.

A detailed study of the glucose fermentation pathway and the modulation of catabolic oxidoreductase activities by energy sources (i.e., glucose versus lactate or fumarate) in Propionispira arboris was performed. 14C radiotracer data show the CO2 produced from pyruvate oxidation comes exclusively from the C-3 and C-4 positions of glucose. Significant specific activities of glyceraldehyde-3-phosphate dehydrogenase and fructose-1,6-bisphosphate aldolase were detected, which substantiates the utilization of the Embden-Meyerhoff-Parnas path for glucose metabolism. The methylmalonyl coenzyme A pathway for pyruvate reduction to propionate was established by detection of significant activities (greater than 16 nmol/min per mg of protein) of methylmalonyl coenzyme A transcarboxylase, malate dehydrogenase, and fumarate reductase in cell-free extracts and by 13C nuclear magnetic resonance spectroscopic demonstration of randomization of label from [2-13C]pyruvate into positions 2 and 3 of propionate. The specific activity of pyruvate-ferredoxin oxidoreductase, malate dehydrogenase, fumarate reductase, and transcarboxylase varied significantly in cells grown on different energy sources. D-Lactate dehydrogenase (non-NADH linked) was present in cells of P. arboris grown on lactate but not in cells grown on glucose or fumarate. These results indicate that growth substrates regulate synthesis of enzymes specific for the methylmalonyl coenzyme A path and initial substrate transformation.

Acyl Coenzyme A↗
PubMed1995

Glutathione is required for maximal transcription of the cobalamin biosynthetic and 1,2-propanediol utilization (cob/pdu) regulon and for the catabolism of ethanolamine, 1,2-propanediol, and propionate in Salmonella typhimurium LT2.

Transcription of the cob/pdu regulon of Salmonella typhimurium is activated by the PocR regulatory protein in response to 1,2-propanediol (1,2-PDL) in the environment. Nutritional analysis and DNA sequencing confirmed that a strain defective in expression of the cob/pdu regulon in response to 1,2-PDL lacked a functional gshA gene. gshA encodes gamma-glutamylcysteine synthetase (L-glutamate:L-cysteine gamma-ligase [ADP forming]; EC 6.3.2.2), the enzyme that catalyzes the first step in the synthesis of glutathione (GSH). The DNA sequence of gshA was partially determined, and the location of gshA in the chromosome was established by two-factor crosses. P22 cotransduction of gshA with nearby markers showed 21% linkage to srl and 1% linkage to hyd; srl was 9% cotransducible with hyd. In light of these data, the gene order gshA srl hyd is suggested. The level of reduced thiols in the gshA strain was 87% lower than the levels measured in the wild-type strain in both aerobically and anaerobically grown cells. 1,2-PDL-dependent transcription of cob/pdu was studied by using M. Casadaban's Mu-lacZ fusions. In aerobically grown cells, transcription of a cbi-lacZ fusion (the cbi genes are the subset of cob genes that encode functions needed for the synthesis of the corrin ring) was 4-fold lower and transcription of a pdu-lacZ fusion was 10-fold lower in a gshA mutant than in the wild-type strain. Expression of the cob/pdu regulon in response to 1,2-PDL was restored when GSH was included in the medium. In anaerobically grown cells, cbi-lacZ transcription was only 0.4-fold lower than in the gshA+ strain; pdu-lacZ transcription was reduced only by 0.34-fold, despite the lower thiol levels in the mutant. cobA-lacZ transcription was used as negative control of gene whose transcription is not controlled by the PocR/1,2-PDL system; under both conditions, cobA transcription remained unaffected. The gshA mutant strain was unable to utilize 1,2-PDL, ethanolamine, or propionate as a carbon and energy source. The defect in ethanolamine utilization appears to be at the level of ethanolamine ammonia-lyase activity, not at the transcriptional level. Possible roles for GSH in ethanolamine, 1,2-PDL, and propionate catabolism are proposed and discussed.

Aerobiosis↗
PubMed2000

prpR, ntrA, and ihf functions are required for expression of the prpBCDE operon, encoding enzymes that catabolize propionate in Salmonella enterica serovar typhimurium LT2.

The genes required for the catabolism of propionate in Salmonella enterica serovar Typhimurium are organized as two transcriptional units (prpR and prpBCDE) that are divergently transcribed from one another. Sequence homology to genes encoding members of the sigma-54 family of transcriptional activators and the identification of a consensus sigma-54 promoter 5' to the prpBCDE operon suggested that PrpR was required to activate expression of this operon. We isolated insertions in prpR and showed that prpR function was needed for growth on propionate as a carbon and energy source. A medium-copy-number plasmid carrying the lacZ gene under the control of the native sigma-54 promoter of prpBCDE was used to study prpBCDE operon expression. Transcription of the lacZ reporter in prpR, ntrA, and ihfB mutants was 85-, 83-, and 15-fold lower than the level of transcription measured in strains carrying the wild-type allele of the gene tested. These data indicated that PrpR, IHF, and transcription sigma factor RpoN were required for the expression of the prpBCDE operon. Further analysis of the involvement of the integration host factor (IHF) protein in the expression of this operon is required due to the well-documented pleiotropic effect the lack of this global regulator has on gene expression. Deletion of the 5' 615-bp portion of the prpR gene resulted in a PrpR(c) mutant protein that activated prpBCDE transcription regardless of the ability of the strain to synthesize 2-methylcitrate, the putative coactivator of PrpR. These results indicate that the N terminus of PrpR is the coactivator-sensing domain of the protein. When placed under the control of the arabinose-inducible promoter P(araBAD), expression of prpR(c) allele by arabinose had a strong negative effect on growth of the cell. It is proposed that this deleterious effect of PrpR(c) may be due to an uncontrolled ATPase activity of PrpR or to cross-activation of genes whose functions negatively affect cell growth under the conditions tested.

Adenosine Triphosphatases↗
PubMed1995

Absence of acidosis in the initial presentation of propionic acidaemia.

The clinical presentation and results of the initial biochemical and haematological investigations in 11 newborn term infants with propionic acidaemia are described. All patients had neurological symptoms. Only four had clinically important acidosis, but all had a raised blood ammonia. A diagnosis of propionic acidaemia should be considered in all newborn infants with unexplained neurological deterioration even in the absence of a metabolic acidosis.

Acidosis↗
PubMed1983

[Biotin deficiency in the germ-free rat and propionic acidemia].

Biotin deficiency was induced in germ-free rats using three experimental protocols. The results showed the important role of biotin during gestation and suckling. The earlier the deprivation, the earlier the deficiency and the severer the symptoms. In this vitamin deficiency, symptoms occurred that were not observed in the control rats, such as the formation of an intestinal volvulus in rats ingesting an L-isoleucine-supplemented diet. The main biochemical anomalies characteristic of propionic acidemia (ketoacidosis and increased urinary elimination of propionic acid) due to propionyl CoA carboxylase deficiency in man were not observed in the rats that were deprived of biotin for 200 days even after a dietary load of L-isoleucine. Only a small urinary excretion of propionyl-glycine and tiglylglycine was observed. We observed a drop in enzymatic propionyl CoA carboxylase activity in the liver that was proportional to the severity of the vitamin deficiency.

Amino Acid Metabolism, Inborn Errors↗
PubMed1995

Neuropathology of propionic acidemia: a report of two patients with basal ganglia lesions.

Propionic acidemia is a rare genetic disorder of amino acid metabolism caused by deficient activity of propionyl coenzyme A carboxylase. Neuropathologic changes previously reported in infants have been white-matter vacuolization or spongiosis. In children who survive beyond infancy, abnormalities have been found primarily in the basal ganglia. We report neuropathologic findings in two patients with propionic acidemia diagnosed in infancy who survived 35 months and 9 years, respectively. Examination of the brain of the 35-month-old boy showed vascular and parenchymal mineralization, focal pallor and spongy change, and foci of acute neuronal injury. These changes were similar to those previously described. The 9-year-old girl was in good metabolic control when she died, and presented a neuropathologic picture not previously described. She was found at autopsy to have acute hemorrhagic lesions in the caudate, putamen, and globus pallidus bilaterally and in the left ventral thalamus. There was focal neuronal loss, but no acute hypoxic/ischemic neuronal injury. Vascular proliferation and swollen endothelial cells were seen in the basal ganglia, thalamus, and substantia nigra, but not in other regions of the brain. Electron microscopy showed swelling of endothelial cells with viable adjacent brain parenchyma. The endothelial changes suggest a breakdown of the blood-brain barrier.

Basal Ganglia Diseases↗
PubMed1999

Pseudoporphyria induced by propionic acid derivatives.

BACKGROUND: Pseudoporphyria is a photosensitive bullous skin disease that is distinguished from porphyria cutanea tarda (PCT) by its normal porphyrin profile. Drugs are a major cause of this disease, and the list of culprits is continually expanding. Nonsteroidal antiinflammatory agents (NSAIDs), especially naproxen and other propionic acid derivatives, appear to be the most common offenders. OBJECTIVE: The study was carried out to increase awareness about the etiology and characteristic features of pseudoporphyria. METHODS: We report two cases of pseudoporphyria caused by naproxen and oxaprozin. We review the current English language literature on this entity and discuss its clinical features, histology, ultrastructure, etiology, and pathophysiology. RESULTS: A 44-year-old man taking naproxen for chronic low back pain and a 20-year-old woman on oxaprozin for rheumatoid arthritis presented with tense bullae and cutaneous fragility on the face and the back of the hands. In both, skin biopsy showed a cell-poor subepidermal vesicle with festooning of the dermal papillae. Direct immunofluorescence revealed staining at the dermal-epidermal junction and around blood vessels with IgG in the first case and with IgG, IgA, and fibrin in the second case. Urine collections and serum samples yielded normal levels of uro- and coproporphyrins. CONCLUSIONS: Most cases of pseudoporphyria are drug-induced. Naproxen, the most common offender, has been associated with a dimorphic clinical pattern: a PCT-like presentation and one simulating erythropoietic protoporphyria in the pediatric population. Other NSAIDs of the propionic acid family can also cause pseudoporphyria.

Adult↗
PubMed1976

Local treatment of psoriasis of the scalp with clobetasol propionate in alcoholic solution: a comparison of once and twice a day application.

A clinical evaluation was carried out in 53 patients with moderate to severe psoriasis of the scalp to assess the effectiveness of a 0.05% alcoholic solution of clobetasol propionate. Patients were treated on a non-selective basis with either a once a day or twice a day application. After a 2-weeks' treatment period, the results showed that there was an excellent or good response in 65% of patients treated once a day and in all of the patients on twice daily application of the topical steroid. It is recommended, therefore, that clobetasol propionate should be applied twice daily for the control of severe cases of psoriasis of the scalp.

Administration, Topical↗
PubMed1975

Acute neonatal nonketotic hyperglycinemia: normal propionate and methylmalonate metabolism.

Propionyl-CoA carboxylase and combined methylmalonyl-CoA (MMA-CoA) racemase and -mutase activities were studied in liver and fibroblasts of two patients with the acute neonatal form of nonketotic hyperglycemia. In all experiments, these enzyme activities studied in tissues of the patients were within the range of healthy control subjects, whereas no propionyl-CoA carboxylase activity was measurable in the fibroblasts of a patient with propionic acidemia. Subcellular fractionation of liver and fibroblasts indicated that the normal amounts of MMA-CoA found after incubation of whole tissue homogenate were formed by propionyl-CoA carboxylase, a mitochondrial enzyme, and not be acetyl-CoA carboxylase, which theoretically could also be involved in the carboxylation of propionyl-CoA. From the above data as well as from clinical and biochemical observations in three patients, it was concluded that there exists a true nonketotic hyperglycinemia which is not related etiologically to the different disorders of the ketotic hyperglycinemia syndrome. True nonketotic hyperglycinemia is not associated with ketoacidosis even after loading with propionate- and MMA precursors. It must be distinguished by exclusion from mild forms of the ketotic hyperglycinemia syndrome which may present clinically as hyperglycinemia without ketosis.

Acute Disease↗
PubMed1976

Hydantoin-5-propionic aciduria in folic acid nondependent formiminoglutamic aciduria observed in two siblings.

Hydantion-5-propionic acid was detected in massive amounts in the urine of two previously described sisters with folic acid nondependent formiminoglutamic aciduria. HPA was identified rigorously, e.g. by gas chromatography-mass spectrometry, and was measured quantitatively by selected ion monitoring (mass fragmentography) using deuterated HPA as internal standard. Before histidine loading, both girls with the postulated formiminotransferase deficiency excreted an amount of HPA more than 50 times greater than the control subjects. After histidine ingestion, HPA excretion was still doubled or tripled. With the exception of the father, the values for the other members of the family also markedly exceeded the normal range and were of the same order of magnitude as in folate deficiency. Measurement of HPA excretion in urine seems to be a valuable supplement or alternative to the enzymatic FIGu test for the detection of general or functional folate deficiency or impaired folate utilization and it will be indispensable for the detection of (as yet unknown) 4-imidazolone-5-propionic acid hydrolase deficiency.

Adolescent↗
PubMed1979

Human propionyl CoA carboxylase: some properties of the partially purified enzyme in fibroblasts from controls and patients with propionic acidemia.

We report some properties of propionyl CoA carboxylase (PCC) partially purified from cultured human fibroblasts obtained from controls and several patients with propionic acidemia. A series of steps (Triton X-100 treatment, high speed centrifugation, ammonium sulfate precipitation, and density gradient centrifugation) led to 100- to 300-fold purification of control enzyme. Control PCC had a molecular weight of nearly 700,000, contained biotin, demonstrated a pH optinum at 8.0-8.5, was activated by potassium, and followed Michaelis-Menten kinetics for each of its substrates. It was distinguished from acetyl CoA carboxylase immunologically as well as by differential purification. Each of seven lines from patients with propionic acidemia had clearly detectable PCC activity which was less than 5% of that in control lines. Although yields were poor and purification less extensive than in control lines, mutant PCC was enriched 2- to 40-fold by the same procedures employed for the control enzyme. Mutant enzyme had a pH optimum, ionic requirements, and substrate Km's similar to those of control PCC, but was distinctly more labile to both cold and heat. These findings suggest that the markedly reduced activity of PCC in these patients results from a mutation in the PCC structural gene locus or loci which leads to the synthesis of altered enzyme protein molecules.

Adult↗
PubMed1980

Propionate inhibition of succinate:CoA ligase (GDP) and the citric acid cycle in mitochondria.

Propionate inhibits oxygen consumption by rat liver mitochondria when glutamate, alpha-ketaglutarate, and succinate are substrates. Carnitine prevents this effect. The pattern of inhibition of 14CO2 release from metabolic intermediates indicates citric acid cycle inhibition between succinate:coenzyme A (CoA) ligase (GDP) and malate dehydrogenase. Propionyl CoA is synthesized from propionate in mitochondria. Propionyl CoA is a potent inhibitor of succinate:CoA ligase with positive cooperativity and half half-maximal inhibition at 2 X 10(-4) M propionyl CoA.

Acyl Coenzyme A↗
PubMed1984

Identification of methyl-branched chain dicarboxylic acids in amniotic fluid and urine in propionic and methylmalonic acidemia.

3-Methyladipic, 4-methylpimelic, 4-methylsuberic, pimelic, and azeleic acids were identified by gas chromatography-mass spectrometry in the amniotic fluid of fetuses with propionic acidemia. These compounds were virtually undetectable in normal amniotic fluid. Concentrations much higher than those of the amniotic fluid were found in the urine of neonatal infants with propionic acidemia and methylmalonic acidemia. It appears that the accumulation of these compounds is a consequence of the accumulation of propionyl-CoA. Evidence was obtained for the presence of other methyl-branched chain dicarboxylic acids. 4-Methylpimelic acid and 4-methylsuberic acid have not previously been identified in human physiological fluids.

Amniotic Fluid↗
PubMed1989

Abnormality of odd-numbered long-chain fatty acids in erythrocyte membrane lipids from patients with disorders of propionate metabolism.

In propionic acidemia and methylmalonic aciduria, disorders of propionate catabolism, excess intracellular propionyl-CoA leads to an enhanced synthesis of odd-numbered long-chain fatty acids. Red cell membrane lipids of patients with these disorders contain pentadecanoic, heptadecanoic, and heptadecenoic acids in excess of normal levels. The odd-numbered long-chain fatty acid content may reflect individual differences in severity of these disorders as well as the degree of effective dietary control. It might be a useful long term parameter for determining the effectiveness of clinical management.

Adolescent↗
PubMed1995

Alterations in the electroretinogram of newborn piglets by propionic acid-derivative nonsteroidal antiinflammatory drugs but not by indomethacin and diclofenac.

Different nonsteroidal antiinflammatory drugs (NSAID), especially ibuprofen, are being considered as an alternative to indomethacin for use in the newborn and as antipyretics for infants. However, some of these NSAID have been shown to cause visual complications. We therefore studied the effects of different NSAID indomethacin 19.6 mumol/kg (7 mg/kg), diclofenac 15.7 mumol/kg (5 mg/kg), ibuprofen 48 and 194 mumol/kg (10 and 40 mg/kg), naproxen 79 mumol/kg (20 mg/kg), and flurbiprofen 41 mumol/kg (10 mg/kg) on photopic and scotopic electroretinograms (ERG) and retinal prostaglandin E2, prostaglandin F2 alpha, and 6-keto-prostaglandin F1 alpha levels in piglets 1-5 d old. All NSAID decreased retinal prostaglandin levels, but their effects on the ERG were not identical. Indomethacin and diclofenac did not alter the ERG. In contrast, the propionic acid derivatives ibuprofen (the two doses used), naproxen, and flurbiprofen affected the amplitude as well as the implicit time of the ERG under photopic and scotopic conditions. These changes are suggestive of generalized alterations in the function of rods and cones. Prior inhibition of prostaglandin synthesis by indomethacin did not modify the effects of ibuprofen on the ERG. These findings thus show a dissociation between the effects of NSAID on the ERG and prostaglandin synthesis. Because ERG changes are associated with visual alterations, these effects of propionic acid derivatives should be taken into account before considering their use in infants.

Animals↗