scholarly journals Oxidation of formate by peroxisomes and mitochondria from spinach leaves

1974 ◽  
Vol 138 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Barry Halliwell

1. Spinach (Spinacia oleracea L.) leaf extracts catalyse the oxidation of formate to CO2. 2. Two enzymic systems are responsible for this oxidation, the peroxidatic action of catalase (EC 1.11.1.6) and NAD-dependent formate dehydrogenase (EC 1.2.1.2). 3. Formate dehydrogenase is mainly, if not exclusively, located in the mitochondria. This enzyme has a pH optimum of 6–6.5 and a Km for formate of 1.7mm in the presence of 1 mm-NAD+. 4. Peroxidatic action of catalase is presumed to take place in peroxisomes, since these seem to be the subcellular site of catalase. Formate oxidation at pH5 by chloroplast and mitochondrial fractions is due to their ability to generate H2O2 and the presence of contaminating catalase. 5. During photorespiration, peroxidatic oxidation of formate by catalase can occur over a wide range of pH values, but the rate of this reaction is probably controlled by the concentration of formate present, to an extent dependent on the pH.

1986 ◽  
Vol 236 (2) ◽  
pp. 475-480 ◽  
Author(s):  
G Arthur ◽  
L Page ◽  
T Mock ◽  
P C Choy

The hydrolysis of the alkenyl bonds of plasmenylcholine and plasmenylethanolamine by plasmalogenase, followed by hydrolysis of the resultant lysophospholipid by lysophospholipase, has been postulated as the major pathway for the catabolism of these plasmalogens. However, the postulation was based solely on the presence of plasmalogenase activity towards plasmenylethanolamine and plasmenylcholine in the brain. In this study we have demonstrated the absence of plasmalogenase activity for plasmenylcholine in the guinea pig heart under a wide range of experimental conditions. Plasmenylcholine was hydrolysed by phospolipase A2 activities in cardiac microsomal, mitochondrial and cytosolic fractions. Phospholipase A2 activities in these fractions had an alkaline pH optimum and were enhanced by Ca2+. The enzymes also displayed high specificity for plasmenylcholine with linoleoyl or oleoyl at the C-2 position. Lysoplasmalogenase activity for lysoplasmenycholine was also detected and characterized in the microsomal and mitochondrial fractions. Since the cardiac plasmalogenase is only active towards plasmenylethanolamine but not plasmenylcholine, the catabolism of these two plasmalogens must be different from each other. We postulate that the major pathway for the catabolism of plasmenycholine involves the hydrolysis of the C-2 fatty acid by phospholipase A2, and hydrolysis of the vinyl ether group of the resultant lysoplasmenylcholine by lysoplasmalogenase.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 30
Author(s):  
Jiri Kos ◽  
Tomas Gonec ◽  
Tomas Strharsky ◽  
Michal Oravec ◽  
Josef Jampilek

In this study, a series of nine 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by fluorine, chlorine and bromine in various positions, was prepared by microwave-assisted synthesis and characterized. The compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The PET-inhibiting activity of the compounds was within a wide range, but rather moderate; the highest activity within the series of the compounds was observed for N-(3,5-difluorophenyl)-3-hydroxynaphthalene-2-carboxamide (IC50 = 9.8 µM). The compounds were found to inhibit PET in photosystem II.


2001 ◽  
Vol 79 (8) ◽  
pp. 897-904 ◽  
Author(s):  
Deborah Lorenzin ◽  
Candace Webb ◽  
Peter S Summers ◽  
Elizabeth A Weretilnyk

S-adenosyl-L-methionine dependent phospho-base N-methyltransferases are involved in the sequential methylations of phosphoethanolamine [Formula: see text] phosphomethylethanolamine [Formula: see text] phosphodimethylethanolamine [Formula: see text] phosphocholine. Phosphocholine is a precursor for the ubiquitous phospholipid phosphatidylcholine and for free choline, which can be oxidized to produce the osmoprotectant glycine betaine. Despite the importance of these enzymes to growth and stress tolerance, their activities have been studied in comparatively few plant species. Phospho-base N-methylating activities were assayed in leaf extracts prepared from 17 diverse plant species. All plants tested can perform the first step ( N-methylation of phosphoethanolamine) with in vitro activity rates varying from 0.13 nmol·min–1·g–1 fresh weight for soybean (Glycine max (L.) Merr.) and pea (Pisum sativum L.) to 25 nmol·min–1·g–1 fresh weight for cotton (Gossypium hirsutum L.). Of the plant species surveyed, only soybean and pea showed no capacity to perform the two subsequent N-methylation steps. Exposing plants to prolonged dark periods led to decreased phosphoethanolamine N-methylating activity relative to light-exposed controls with the extent of decrease varying among the species from 30% (Limonium perezii (Stapf) F.T. Hubb) to over 90% (Spinacia oleracea L., Beta vulgaris L., and Amaranthus caudatus L.). Thus, light-responsive properties and levels of phosphobase methyltransferase activities vary among plants with a trend towards higher activities being found in plants that accumulate glycine betaine.Key words: glycine betaine, choline, phosphatidylcholine, phosphocholine.


Author(s):  
Debashree Das ◽  
Shailendra Patil ◽  
Asmita Gajbhiye

Aim: Synthetic lead molecules are associated with host of adverse effects while medicinal molecules isolated from natural sources are blessed with both safety as well as efficacy. The ancient doctrine of Ayurveda ardently advocates the therapeutic virtues contained in green leaves of Spinacia oleracea L. The principal constituent of the leaves is the class of metalloporphyrin chlorophyll, which is also the floral counterpart of faunal heme. Chlorophyll-a (Chl-a) and chlorophyll-b (Chl-b) are the cardinal members of the chlorophyll family. Study design: Herein, we have explored the anti-radical, cytoprotective, anti-inflammatory and anti-proliferative efficacy of Chl-a and Chl-b in reference to standard drug and crude extract of Spinacia leaves. The current study is aimed to establish, naturally mined metaloporphyrins as safe and efficacious replacement of synthetic leads that are associated with a wide range of toxicological issues. Methodology: Using a combination of Silica Gel-G column chromatography and preparative thin layer chromatography, the two principal green metallo-porphyrins (Chl-a and Chl-b) were sequentially extracted and isolated from crude extract of Spinacia oleracea L leaves. Antiradical efficacy, of the isolated green porphyrins was quantified by DPPH and Hydrogen peroxide radical scavenging assay. Cytoprotective efficacy was evaluated using ex-vivo hemolysis assay and anti-inflammatory potency was attested employing carrageenan induced paw edema bioassay. To enumerate on the anti-proliferative potency, MTT assay was employed, while toxicology of the isolates was evaluated employing OECD 420 acute toxicity guidelines. Findings: The study confirmed that isolated green porphyrins Chl-a and Chl-b as well as crude extract all exerts significant anti-radical, cytoprotective, anti-inflammatory and anti-proliferative efficacy however while potency of Chl-a was at par with that of reference standard and superior to the crude extract, Chl-b clocked in a value inferior to both. Furthermore, acute toxicity study indicated that even at p.o. dose of 2000mg/Kg b.w, no toxicity was manifested in either of the metalloporpyrin treated groups thus ascertaining the safe nature of the naturally mined metalloporphyrin entities. Also naturally mined Chl-a is not only a safer alternative to synthetic medicine but it is more potent and safe than its parent extract popularly used in herbal medicine. Conclusion:  The results of the study indicates that Chl-a having a more profound structural resemblance to heme than Chl-b can be further modulated as a cost-effective and safe anti-radical alternative to synthetic leads in inhibiting inflammation and untoward cell proliferative while extending cyto-protection from pathological ROS generated in diseased states.


1950 ◽  
Vol 28c (6) ◽  
pp. 673-689 ◽  
Author(s):  
E. R. Waygood ◽  
K. A. Clendenning

Carbonic anhydrase was found in leaf extracts prepared from 19 of 22 land and aquatic plant species examined. The most active preparations were obtained from Spinacia oleracea L., Tetragonia expansa Thunb., Tropaeolum majus L., and Sambucus canadensis L. Carbonic anhydrase is located in the leaf cytoplasm. Previously conflicting observations concerning its intracellular localization have been reconciled experimentally. Plant carbonic anhydrase is strongly inhibited by M/1000 azide, M/1000 cyanide, and M/2000 sulphanilamide and is weakly inhibited by 2,4-dichlorophenoxyacetic acid, diethyldithiocarbamate, and o-phenanthroline. The white zones of variegated Tradescantia leaves contain 50% less carbonic anhydrase than their green counterparts. Albino barley leaves contain 75% less carbonic anhydrase than normal barley leaves of the same size and age. The carbonic anhydrase content of green leaves kept in darkness for four and five days was lowered by 30–50%. Very young leaves contain less enzyme than mature leaves. These results are discussed in relation to the possible role of carbonic anhydrase in photosynthesis.


2019 ◽  
Vol 35 (6) ◽  
pp. 21-29
Author(s):  
T.E. Leonova ◽  
T.E. Shustikova ◽  
T.V. Gerasimova ◽  
Т.А. Ivankova ◽  
K.V. Sidorenko Sidorenko ◽  
...  

Thepsefdh_D221Q gene coding for a mutant formate dehydrogenase (PseFDG_D221Q) from Pseudomonas, which catalyzes the formate oxidation with the simultaneous formation of NADPH, has been expressed in the cells of lysine-producing Corynebacterium glutamicum strains. The psefdh_D221Q gene was introduced into С. glutamicum strains as part of an autonomous plasmid or was integrated into the chromosome with simultaneous inactivation of host formate dehydrogenase genes. It was shown that the С. glutamicum strains with NADP+ -dependent formate dehydrogenase have an increased level of L-lysine synthesis in the presence of formate, if their own formate dehydrogenase is inactivated. L-lysine, formate dehydrogenase, NADPH, Corynebacterium glutamicum The work was carried out using the equipment of the Multipurpose Scientific This work was carried out on the equipment of the Multipurpose Scientific Installation of «All-Russian Collection of Industrial Microorganisms», National Bio-Resource Center, NRC «Kurchatov Institute»- GosNIIgenetika. This work was financially supported by the Ministry of Education and Science of Russia (Unique Project Identifier - RFMEFI61017X0011).


1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.


2016 ◽  
Vol 5 (11) ◽  
pp. 5110
Author(s):  
Sartaj Ahmad Allayie ◽  
Mushtaq Ahmed Parray* ◽  
Bilal Ahmad Bhat ◽  
S. Hemalatha

The use of traditional medicines holds a great promise as an easily available source as effective medicinal agents to cure a wide range of ailments among the people particularly in tropical developing countries like India. The present study investigates the qualitative and quantitative analysis of the major bioactive constituents of N. crenulata leaf extracts. The extractive values of aqueous, acetone and chloroform extracts were found to be 11.34, 4.24 and 6.06 respectively. Qualitative phytochemical analysis of these three solvent extracts confirm the presence of Alkaloids, Saponins, Flavonoids and Phenolic compounds in all the three extracts; however, these phytochemicals were more significant in aqueous extract. Quantitative analysis was carried out using TLC method by different solvent system. Amongst various solvent systems, Butanol: acetic acid: water (9: 0.9: 0.1 v/v/v) shows maximum resolution and number of spots produced at long UV (365 nm) and under iodine vapours. The TLC chromatograms constituted different coloured phytochemical compounds with different Rf values. It can be conveniently used to evaluate the quality of different area samples. This indicates that the leaves can be useful for treating different diseases because the therapeutic activity of a plant is due to the presence of particular class of compounds and thus can serve as potential sources of useful drugs in future.


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