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PubMed2001

Construction of an expression vector for propionibacteria and its use in production of 5-aminolevulinic acid by Propionibacterium freudenreichii.

Several promoters from Propionibacterium freudenreichii subsp. shermanii were isolated using a promoter probe vector, pCVE1, containing the Streptomyces cholesterol oxidase gene (choA) as a reporter gene. Three of four promoters isolated exhibiting a strong activity in Escherichia coli also expressed a strong activity in P. freudenreichii subsp. shermanii IFO12426. Using two promoters with a strong activity and a previously constructed shuttle vector, pPK705, shuttling between E. coli and Propionibacterium. we constructed expression vectors for propionibacteria. To overproduce 5-aminolevulinic acid (ALA), which is the first intermediate in the synthesis of porphyrins, the ALA synthase gene (hemA) from Rhodobacter sphaeroides was recombined with the expression vectors. The activity of ALA synthase in the recombinant P freudenreichii subsp. shermanii increased about 70-fold that in the strain without a vector. The recombinant Propionibacterium produced ALA at a maximum concentration of 8.6 mM in the absence of levulinic acid, an inhibitor of ALA dehydratase, with 1% glucose as a carbon source. The recombinant P. freudenreichii accumulated 18.8 mmol/g cells ALA in the presence of 1 mM levulinic acid and 30 mM glycine. The construction of an efficient expression vector will facilitate genetic studies of a vitamin B12 producer, Propionibacterium.

Aminolevulinic Acid↗
PubMed1975

Control of delta-Aminolevulinic Acid and Chlorophyll Accumulation in Greening Maize Leaves upon Light-Dark Transitions.

The accumulation of delta-aminolevulinic acid (ALA) was studied in greening maize (Zea mays) leaves which were transferred to darkness and reilluminated after various periods of time. The system synthesizing ALA decays in the dark with a half-life of about 80 minutes. The onset of enzyme decay after transfer to darkness shows a 40-minute lag. The accumulation of ALA in the presence of levulinic acid in leaves transferred to darkness corresponds to that expected from the estimated half-life of the enzyme synthesizing ALA. On the other hand, the accumulation of protochlorophyll upon transfer to darkness in the absence of levulinic acid stops much earlier. It is suggested that a control point exists in the pathway between ALA and protochlorophyll, preventing utilization of the accumulated ALA upon transfer of greening leaves to darkness. This is supported by the observed effects of low intensities of monochromatic light (648 nm) on ALA and chlorophyll accumulation.

Journal Article↗
PubMed1980

Effect of an exogenous succinyl-CoA-generating system on the measurement of delta-aminolevulinic acid synthase activity in rat liver tissue by a radiochemical assay.

Rat liver tissue was used to examine the effect of an exogenous succinyl-CoA-generating system on the radiochemical assay for delta-aminolevulinic acid synthase (succinyl-CoA:glycine C-succinyltransferase (decarboxylating), EC 2.3.1.37) activity developed by Ebert et al. (Ebert, P.S., Tschudy, D.P., Choudry, J.N. and Chirigos, M.A. (1970) Biochim. Biophys. Acta 208, 236--250). In the absence of exogenous succinate thiokinase, 34--62% (average 55%) of the radioactivity in the final column eluate could be attributed to delta-amino-[4-14C]levulinic acid, as assessed by conversion of delta-aminolevulinic acid in the eluate to a pyrrole. The addition of succinate thiokinase markedly enhanced the formation of the contaminant(s), as succinyl-CoA was metabolized to a compound or compounds that eluted chromatographically with delta-amino-levulinic acid. This effect was abolished by 10 mM EDTA, probably because the generation of succinyl-CoA was suppressed due to the chelation of Mg2+. These observations indicate that this radiochemical assay should be carefully examined for each set of assay conditions employed.

5-Aminolevulinate Synthetase↗
PubMed1990

Regulation of 5-Aminolevulinic Acid (ALA) Synthesis in Developing Chloroplasts : III. Evidence for Functional Heterogeneity of the ALA Pool.

Gabaculine and 4-amino-5-hexynoic acid (AHA) up to 3.0 millimolar concentration strongly inhibited 5-aminolevulinic acid (ALA) synthesis in developing cucumber (Cucumis sativus L. var Beit Alpha) chloroplasts, while they hardly affected protochlorophyllide (Pchlide) synthesis. Exogenous protoheme up to 1.0 micromolar had a similar effect. Exogenous glutathione also exhibited a strong inhibitory effect on ALA synthesis in organello but hardly inhibited Pchlide synthesis. Pchlide synthesis in organello was highly sensitive to inhibition by levulinic acid, both in the presence and in the absence of gabaculine, indicating that the Pchlide was indeed formed from precursor(s) before the ALA dehydratase step. The synthesis of Pchlide in the presence of saturating concentrations of glutamate was stimulated by exogenous ALA, confirming that Pchlide synthesis was limited at the formation of ALA. The gabaculine inhibition of ALA accumulation occurred whether levulinic acid or 4,6-dioxohepatonic acid was used in the ALA assay system. ALA overproduction was also observed in the absence of added glutamate and was noticeable after 10-minute incubation. These observations suggest that although Pchlide synthesis in organello is limited by ALA formation, it does not utilize all the ALA that is made in the in organello assay system. Gabaculine, AHA, and probably also protoheme, inhibit preferentially the formation of that portion of ALA that is not destined for Pchlide. A model proposing a heterogenous ALA pool is described.

Journal Article↗
PubMed1978

The role of vanadium in green plants. IV. Influence on the formation of delta-aminolevulinic acid in Chlorella.

In a series of experiments, it is demonstrated that the trace element vanadium (4.10(-7) g-at/1 as NH4VO3) has a considerable positive influence on the synthesis of delta-aminolevulinic acid(delta-ALA) in the autotrophically growing green alga Chlorella pyrenoidosa, the effect being visible by an enhanced output of the amino acid into the culture medium in presence of levulinic acid (LA). The level of intracellularly accumulated delta-ALA, however, is not changed in presence of the metal. The V-effect on exogenous found delta-ALA is suppressed, when LA is added to the nutrient medium at low pH (pH5), although V-uptake into the algal cells is not disturbed by LA. As demonstrated in culture media with various nitrogen sources (urea, partially hydrolized urea, ammonium salts), the development of the pH during the cultivation time is important for the presentation of the V-effect on delta-ALA. It is suggested that vanadium acts as a catalyst in the conversion of 4,5-dioxovaleric acid to delta-ALA by transamination.

Aminolevulinic Acid↗
PubMed1970

The biosynthesis of delta-aminolevulinic acid in Chlorella.

When autotrophically growing cultures of Chlorella are treated with levulinic acid, delta-aminolevulinic acid is excreted into the medium, providing a direct demonstration of alpha-aminolevulinic acid production in a green plant. Evidence is presented which indicates that alpha-aminolevulinic acid formation may be the the rate-controlling step of chlorophyll synthesis in Chlorella, and that control of the rate of alpha-aminolevulinic acid synthesis may be exerted at the level of production and breakdown of an enzyme which catalyzes its formation.

Amino Acids↗
PubMed1977

Effects of selenium and vitamin E deficiencies in lambs on hepatic microsomal hemoproteins and mitochondrial respiration.

Microsomal hemoprotein levels and delta-amino levulinic acid dehydrase activity were determined in livers and rate of oxygen uptake, ADP:O ratios, and respiration control index were determined on mitochondria from muscle, liver, and heart of normal and white muscle diseased (WMD) lambs. WMD lambs were produced by feeding their dams either low selenium purified or alfalfa hay diets. Vitamin E and/or selenium was injected in a 2 x 2 factorial treatment in the ewes fed purified diets. Hepatic microsomal cytochrome P 450 levels and total heme content were significantly lower in WMD lambs. Cytochrome b5 content was significantly lower in lambs on the -E-Se or -E + Se treatments than those on the +E--Se treatment, but the cytochrome b5 content was not different between WMD and normal lambs from ewes fed the hay diet. No differences were found in hepatic delta-amino levulinic acid dehydrase activity, or in the rate of oxygen uptake, ADP:O ratios or respiratory control index between mitochondria from normal and WMD lamb tissue on any of the treatments.

Animals↗
PubMed2002

Comparison of the fermentability of enzymatic hydrolyzates of sugarcane bagasse pretreated by steam explosion using different impregnating agents.

Sugarcane bagasse is a potential lignocellulosic feedstock for ethanol production, since it is cheap, readily available, and has a high carbohydrate content. In this work, bagasse was subjected to steam explosion pretreatment with different impregnation conditions. Three parallel pretreatments were carried out, one without any impregnation, a second with sulfur dioxide, and a third with sulfuric acid as the impregnating agent. The pretreatments were performed at 205 degrees C for 10 min. The pretreated material was then hydrolyzed using cellulolytic enzymes. The chemical composition of the hydrolyzates was analyzed. The highest yields of xylose (16.2 g/100 g dry bagasse), arabinose (1.5 g/100 g), and total sugar (52.9 g/100 g) were obtained in the hydrolysis of the SO2 -impregnated bagasse. The H2SO4 -impregnated bagasse gave the highest glucose yield (35.9 g/100 g) but the lowest total sugar yield (42.3 g/100 g) among the three methods. The low total sugar yield from the H2SO4-impregnated bagasse was largely due to by-product formation, as the dehydration of xylose to furfural. Sulfuric acid impregnation led to a three-fold increase in the concentration of the fermentation inhibitors furfural and 5-hydroxymethylfurfural (HMF) and a two-fold increase in the concentration of inhibitory aliphatic acids (formic, acetic, and levulinic acids) compared to the other two pretreatment methods. The total content of phenolic compounds was not strongly affected by the different pretreatment methods, but the quantities of separate phenolic compounds were widely different in the hydrolyzate from the H2SO4-impregnated bagasse compared with the other two hydrolyzates. No major differences in the content of inhibitors were observed in the hydrolyzates obtained from SO2-impregnated and non-impregnated bagasse. The fermentability of all three hydrolyzates was tested with a xylose-utilizing Saccharomyces cerevisiae strain with and without nutrient supplementation. The hydrolyzates of SO2-impregnated and nonimpregnated bagasse showed similar fermentability, whereas the hydrolyzate of H2SO4-impregnated bagasse fermented considerably poorer.

Cellulase↗
PubMed1988

Transformation of glutamate to delta-aminolevulinic acid by soluble extracts of Synechocystis sp. PCC 6803 and other oxygenic prokaryotes.

delta-Aminolevulinic acid is the first committed precursor in the biosynthesis of hemes, phycobilins, and chlorophylls. Plants and algae synthesize delta-aminolevulinic acid from glutamate via an RNA-dependent 5-carbon pathway. Previous reports demonstrated that cyanobacteria form delta-aminolevulinic acid from glutamate in vivo. We now report the direct measurement of this activity in vitro. Three oxygenic prokaryotes were examined, the unicellular cyanobacteria Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002 (Agmenellum quadruplicatum PR-6) and the chlorophyll a- and b-containing filamentous prochlorophyte Prochlorothrix hollandica. delta-Aminolevulinic acid-forming activity was detected in soluble extracts of all three species. delta-Aminolevulinic acid formation by Synechocystis extracts was further characterized. Activity depended upon addition of reduced pyridine nucleotide, ATP, and Mg2+ to the incubation mixture. NADPH was a more effective pyridine nucleotide than NADH at low concentrations, but NADPH inhibited delta-amino-levulinic acid formation above 1 mM, whereas NADH did not. The pH optimum was about 7.6, and the ATP concentration optimum was 0.1 mM. Activity was stimulated by addition of RNA derived from Synechocystis or Chlorella, and abolished by preincubation with RNase A. After RNase inactivation, activity was restored by addition of RNasin to block further RNase action, followed by supplementation with Synechocystis RNA. Activity was inhibited by micromolar concentrations of hemin, as was previously found with plant and algal extracts. Complete dependence on added glutamate could not be achieved. Radioactivity was incorporated into delta-aminolevulinic acid when the incubation mixture contained 1-[14C]glutamate. Activity in the Synechocystis enzyme extract was stimulated by the addition of a partially purified enzyme fraction from Chlorella. It thus appears that prokaryotic oxygenic organisms share with chloroplasts the capacity for biosynthesis of photosynthetic pigments from glutamate via the RNA-dependent 5-carbon pathway.

Aminolevulinic Acid↗
PubMed1989

Biosynthesis of Tetrapyrrole Pigment Precursors : Pyridoxal Requirement of the Aminotransferase Step in the Formation of delta-Aminolevulinate from Glutamate in Extracts of Chlorella vulgaris.

The aminotransferase that catalyzes the formation of delta-aminolevulinic acid from glutamate-1-semialdehyde or from glutamate in a reconstituted enzyme system was isolated and partially purified from Chlorella vulgaris. The apparent molecular weight of the aminotransferase was determined by Sephadex G-100 and Ultrogel AcA 54 gel filtration to be 60,000 +/- 5,000. Catalytic activity of the aminotransferase required pyrixodal phosphate (PALP). The cofactor could not be removed by gel filtration after exposure of the enzyme to PALP. Aminotransferase was inhibited by gabaculine (3-amino-2,3-dihydrobenzoic acid). The concentration of gabaculine required for half maximal inhibition was about 0.05 micromolar. Aminotransferase activity could be regained upon the removal of gabaculine by gel filtration and supplementing the assay medium with PALP. Neither the inhibitory action of gabaculine nor its reversibility was affected by preincubation of the enzyme with the keto acids levulinate and delta-aminolevulinic acid.

Journal Article↗
PubMed1998

Preferential relative porphyrin enrichment in solar keratoses upon topical application of delta-aminolevulinic acid methylester.

Topically applied delta-aminolevulinic acid is used efficiently for the treatment of solar keratoses by photodynamic therapy. Recent animal studies suggest that porphyrin sensitization of epithelial tissue is improved by using esters rather than free delta-aminolevulinic acid. The present study examines porphyrin metabolite formation after topical application of delta-aminolevulinic acid or delta-amino-levulinic acid methylester in human solar keratoses versus adjacent normal skin. Level of total porphyrins, porphyrin metabolites and protein were measured in skin samples excised after 1 and 6 h. Higher levels of porphyrins were observed in solar keratoses than in normal skin with both substances. Maximum porphyrin levels were present in solar keratoses treated with delta-aminolevulinic acid for 6 h. However, the ratio of porphyrins in solar keratoses versus adjacent normal skin was higher with delta-aminolevulinic acid methylester. The pattern of porphyrins showed no significant difference between normal and afflicted skin, protoporphyrin being predominant. The results suggest that application of free delta-aminolevulinic acid may be more effective in sensitizing solar keratoses. However, treatment with delta-aminolevulinic acid methylester leads to a preferential enrichment of porphyrins within lesional skin.

Administration, Topical↗
PubMed1980

Biosynthesis of 5-aminolevulinate from glutamate in Anabaena variabilis.

Anabaena variabilis filaments excrete 5-aminolevulinate into the medium when incubated in the presence of levulinic acid, a competitive inhibitor of the 5-aminolevulinate utilizing enzyme, 5-aminolevulinate dehydratase (5-aminolevulinate hydro-lyase, EC 4.2.1.24). Although 5-aminolevulinate accumulation is independent of an external supply of substrate, the accumulating 5-aminolevulinate can be readily labeled by [14C]glutamate or alpha-[14C]ketoglutarate. Glycine and succinate, substrates of the classical 5-aminolevulinate synthesizing enzyme, 5-aminolevulinate synthase (succinyl-CoA:glycine C-succinyltransferase (decarboxylating), EC 2.3.1.37), label 5-aminolevulinate only to a very small extent. Studies with glutamate and alpha-ketoglutarate labeled in specific carbon atoms show that in A. variabilis, as in higher plants and eukaryotic algae, all five carbon atoms of these substrates are incorporated into 5-aminolevulinate, with carbon 1 of glutamate or of alpha-ketoglutarate becoming carbon 5 of 5-amino-levulinate. These findings are consistent with the theory that chloroplasts evolved from cyanobacteria or from closely related organisms.

Aminolevulinic Acid↗
PubMed1982

Influence of allyl isopropyl acetamide on d-aminolevulinic acid and aminoacetone synthesis during postnatal development in rats.

In contrast to other groups we found an allyl isopropyl acetamide (AIA)-mediated induction of aminoketones (AK) in newborn rats. To further clarify this phenomenon, the development of d-amino-levulinic acid synthesis (ALAS) and aminoacetone synthesis (AAS) and their inducibility by AIA were determined during the first days of life, daily until the 5th day of life, and then up to an age of 240 days. Both ALAS and AAS decrease during the first 24 h of life; the inducibility of both is detectable 6 h after birth, and develops during the first day of life to reach maximal inducibility. Minimum values are observed between day 30-45 of life; thereafter a tendency of increasing basic activity (AAS) and constant (ALAS) or decreasing (AAS) inducibility is detectable.

5-Aminolevulinate Synthetase↗
PubMed1986

[Urinary delta-aminolevulinic acid levels in dairy cows during lead loading from feed rations under normal conditions of rearing in the Western Slovakia Region].

The concentration of delta-amino levulinic acid (ALA) was determined in the urine of clinically healthy cows of 14 herds in the West-Slovakian region. The content of lead was determined at the same time in the components of feed rations. The ALA concentration values were converted to values per uniform specific weight of urine and per gram of secreted creatinine to match literary sources where the ALA concentration is given in these two quantities. The approximate intake of lead by the animal bodies in milligrams per head/day and per kg of live weight was calculated from lead content in feed rations. The average ALA concentration in the urine of dairy cows was 42.7 +/- 20.2 mu mol per 1 of urine (36.8 +/- 18.7 mu mol per g of creatinine), the average lead intake from feed being 0.157 mg per kg of live weight. The ALA concentrations in urine refer to animals given normal feeds with no lead contamination and as such can be considered as physiological values. Statistically significant correlations were recorded between ALA concentrations per litre of urine at the uniform specific weight of 1030 g per litre and the values converted per gram of secreted creatinine (r = 0.789). The upper biological tolerance limit of ALA concentration in urine (105.0 mu mol per litre) was determined by mathematico-statistical methods. Values above this limit could be indicative of an increased lead stress of the cows' bodies.

Aminolevulinic Acid↗
PubMed1981

Experimental porphyric neuropathy: a preliminary report.

An experimental model for the study of porphyric neuropathy is presented. Injection of either tetraphenyl-porphinesulfonate (TPPS), hematoporphyrin derivative (HpD), or delta-amino-levulinic acid (ALA) into mice resulted in markedly decreased motor nerve conduction velocity (MNCV). THe MNCV returned to normal within one week following the injection of large doses of ALA, and within three weeks following the injection of close to lethal doses of HpD, but there was no recovery of nerve function within 50 days following injection of substantially smaller doses of TPPS. Ultrastructural examination of motor nerves at various times following TPPS injection revealed the gradual development of structural abnormalities. Ultrastructural examination of the same nerves after a single dose of either ALA or HpD failed to demonstrate any abnormalities. The present observations call for precaution as to the use of TPPS as photosensitizer in human cancer treatment.

Aminolevulinic Acid↗