1,721,039 research outputs found
Purification of euphorbia characias latex peroxidase by calmodulin-affinity chromatography
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Purification, primary structure, and properties of Euphorbia characias latex purple acid phosphatase
No full textA purple acid phosphatase was purified to homogeneity from Euphorbia characias latex. The native protein has a molecular mass of 130 +/- 10 kDa and is formed by two apparently identical subunits, each containing one Fe(III) and one Zn(II) ion. The two subunits are connected by a disulfide bridge. The enzyme has an absorbance maximum at 540 nm, conferring a characteristic purple color due to a charge-transfer transition caused by a tyrosine residue (Tyr172) coordinated to the ferric ion. The cDNA nucleotide sequence contains an open reading frame of 1392 bp, and the deduced sequence of 463 amino acids shares a very high degree of identity (92-99%) to other purple acid phosphatases isolated from several higher plants. The enzyme hydrolyzes well p-nitrophenyl phosphate, a typical artificial substrate, and a broad range of natural phosphorylated substrates, such as ATP, ADP, glucose-6-phosphate, and phosphoenolpyruvate. The enzyme displays a pH optimum of 5.75 and is inhibited by molybdate, vanadate, and Zn(2+), which are typical acid phosphatase inhibitors
Evaluation of antioxidant, anti-tyrosinase potentials and phytochemical composition of four Egyptian plants
No full textThe aim of this present research is to evaluate antioxidant and antityrosinase potentials and to investigate the phytoconstituents of methanol (70%) extract from four Egyptian plants, Solanum rantonnetii, Tilia cordata, Cichorium intybus (L.), and Lagerstroemia tomentosa. Antioxidant activity was measured by using two different free radical scavenging methods, 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), whereas polyphenols and flavonoids contents were evaluated by using Folin-Ciocalteau, and aluminum nitrate methods respectively. Tyrosinase inhibition was evaluated using commercial enzyme and dihydroxyphenylalanine (DOPA) as substrate and methanol extract of each plant was investigated by phytochemical analysis. The results showed that all the plants had good antioxidant activity where Cichorium intybus exhibited the highest antioxidant activity determined as total content of free-radical scavenging, polyphenol and flavonoid molecules, and showed the best tyrosinase inhibition activity compared with the other plants extracts studied. Chromatogarphic separation and NMR analysis of Cichorium intybus methanol extract revealed the identification of two coumarins, scopoletin and esculetin, and seven flavonoids, dihydroquercetin 7-4'-dimethyl ether, blumeatin, diosmetin, tamarixetin, quercetin, quercetin 3-O-β-galactoside and kaempferol 3-O-rutinoside. These findings suggest that Cichorium intybus is rich with bioactive compounds and could be used as a good source of potentially natural antioxidants and antityrosinase molecules
Calcium ions and a secreted peroxidase in Euphorbia characias latex are made for each other
No full textThis minireview deals of a protein, a class III secreted peroxidase, present as unique isoform in the latex of the perennial Mediterranean shrub Euphorbia characias. The paper reports on the molecular properties, on the structures (primary, secondary and tertiary), and on the catalytic mechanism of this enzyme. Here is also reported the extraordinary effect of calcium ions on the structure and on the enzyme activity of Euphorbia peroxidase. These ions can either enhance the catalytic efficiency of the enzyme toward some substrates or can regulate the ability of the enzyme to execute different metabolic pathways toward the same substrate. This review will give a valuable reference to the peroxidase fans and the general readers will find many thorough suggestions for future researches giving birth to new studies and important discoveries
Purification and characterisation of a soluble nucleotide pyrophosphatase/phosphodiesterase from prickly pear (Opuntia ficus indica) fruits
No full textA glycosylated metallo-protein, nucleotide pyrophosphatase/phosphodiesterase, in a soluble form was purified to homogeneity from prickly pear (Opuntia ficus indica) fruits. The native protein had a molecular mass of 105 +/- 8 kDa and was formed by two apparently identical subunits each containing 1 Ca(2+) and 1 Mg(2+) ion. The Opuntia enzyme exhibited hydrolytic activities toward pyrophosphate/phosphodiester bonds of a broad range of natural substrates, but among these, only NAD(P) and NAD(P)H were hydrolysed very efficiently. Moreover, Opuntia pyrophosphatase/phosphodiesterase hydrolysed the artificial substrate thymidine 5'-monophosphate 4-nitrophenyl ester, whereas it did not show any catalytic activity toward bis-4-nitrophenyl phosphate, which is a substrate of other pyrophosphatase/phosphodiesterase enzymes. We observed an increase of enzyme activity from the green to the red stage of fruits development, suggesting that ONPP activity might be related to the ripening of prickly pears. The protein was shown to be resistant to 75 degrees C for 30 min. Other biochemical characteristics were investigated and are reported here
Euphorbia characias latex amine oxidase and peroxidase: Interacting enzymes?
No full textThis minireview deals the enzymatic transformation of some amino acids as arginine and ornithine, amines as tyramine, putrescine, spermine and spermidine, and other substances as nitric oxide and thiocyanate. These reactions, catalyzed by two proteins purified from the latex of Euphorbia characias, a copper/quinone containing amine oxidase and a cationic peroxidase, show enzymatic activity interactions probably occurring between these proteins in Euphorbia latex
Oxidation of di- and polyamines: In vitro effect of amino aldehydes on the vitality of Leishmania promastigotes
No full textThe aminoaldehydes 4-aminobutanal and 5-aminopentanal, derived from the oxidation of the diamines putrescine and cadaverine, and 1-(3-aminopropyl)-4- aminobutanal and aminodialdehyde, derived from the oxidation of the polyamines spermidine and spermine, were produced utilizing a copper amine oxidase (CAO) from Euphorbia characias latex and tested with in vitro cultivation of Leishmania infantum promastigotes. Whereas the aminoaldehydes derived from the oxidation of the diamines were stimulating factors for growth of Leishmania infantum promastigotes, the aldehydes derived from polyamines oxidation had a drastic inhibitory effect on the vitality and growth of these parasites. Thus, a double scenario arises, showing the use of aldehydes from diamines to obtain a large number of organisms of Leishmania infantum promastigotes to use in serological studies, whereas the aldehydes derived from polyamines could be used as a new strategy for therapeutic treatment against these parasites
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