36 resultados para Cadaverine
Resumo:
The structure of cadaverine dihydrochloride monohydrate has been determined by X-ray crystallography with the following features: NH3+(CH2)5NH3+.2Cl-.H2O, formula weight 191.1, monoclinic, P2, a = 11.814(2) angstrom, b = 4.517(2) angstrom, c = 20.370(3) angstrom, beta = 106.56-degrees(1): V = 1041.9(2) angstrom3, lambda = 1.541 angstrom; mu = 53.4 1; T = 296-degrees; Z = 4, D(x) = 1.218 g.cm-3, R = 0.101 for 1383 observed reflections. The crystal is highly pseudosymmetric with 2 molecules of cadaverine, 4 chloride ions and 2 partially disordered water molecules present in the asymmetric unit. Though both the cadaverine molecules in the asymmetric unit have an all trans conformation, the carbon backbones are slightly bent. Between the concave surfaces of two bent cadaverine molecules exists water channels all along the short b axis. The water molecules present in the channels are partially disordered
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While applications of amine oxidases are increasing, few have been characterised and our understanding of their biological role and strategies for bacteria exploitation are limited. By altering the nitrogen source (NH4Cl, putrescine and cadaverine (diamines) and butylamine (monoamine)) and concentration, we have identified a constitutive flavin dependent oxidase (EC 1.4.3.10) within Rhodococcus opacus. The activity of this oxidase can be increased by over two orders of magnitude in the presence of aliphatic diamines. In addition, the expression of a copper dependent diamine oxidase (EC 1.4.3.22) was observed at diamine concentrations>1mM or when cells were grown with butylamine, which acts to inhibit the flavin oxidase. A Michaelis-Menten kinetic treatment of the flavin oxidase delivered a Michaelis constant (KM)=190μM and maximum rate (kcat)=21.8s(-1) for the oxidative deamination of putrescine with a lower KM (=60μM) and comparable kcat (=18.2s(-1)) for the copper oxidase. MALDI-TOF and genomic analyses have indicated a metabolic clustering of functionally related genes. From a consideration of amine oxidase specificity and sequence homology, we propose a putrescine degradation pathway within Rhodococcus that utilises oxidases in tandem with subsequent dehydrogenase and transaminase enzymes. The implications of PUT homeostasis through the action of the two oxidases are discussed with respect to stressors, evolution and application in microbe-assisted phytoremediation or bio-augmentation.
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A transamidinase was purified 463-fold from Lathyrus sativus seedlings by affinity chromatography on homoarginine--Sepharose. The enzyme exhibited a wide substrate specificity, and catalysed the reversible transfer of the amidino groups from donors such as arginine, homoarginine and canavanine to acceptors such as lysine, putrescine, agmatine, cadaverine and hydroxylamine. The enzyme could not be detected in the seeds, and attained the highest specific activity in the embryo axis on day 10 after seed germination. Its thiol nature was established by strong inhibition by several thiol blockers and thiol compounds in the presence of ferricyanide. In the absence of an exogenous acceptor, it exhibited weak hydrolytic activity towards arginine. It had apparent mol.wt. 210000, and exhibited Michaelis--Menten kinetics with Km 3.0 mM for arginine. Ornithine competitively inhibited the enzyme, with Ki 1.0 mM in the arginine--hydroxylamine amidino-transfer reaction. Conversion experiments with labelled compounds suggest that the enzyme is involved in homoarginine catabolism during the development of plant embryo to give rise to important amino acids and amine metabolites. Presumptive evidence is also provided for its involvement in the biosynthesis of the guanidino amino acid during seed development. The natural occurrence of arcain in L. sativus and mediation of its synthesis in vitro from agmatine by the transamidinase are demonstrated.
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The binding of the fluorescent probes 1-anilino-8-naphthalene sulfonate and dansyl cadaverine to the sodium salts of cholic, deoxycholic and dehydrocholic acids has been investigated. Enhanced probe solubilisation accompanies aggregation. Monitoring of fluorescence intensities as a function of bile salt concentration permits the detection of primary micelle formation, as well as secondary association. The transition concentrations obtained by fluorescence are in good agreement with values determined for the critical micelle concentrations, by other methods. Differences in the behaviour of cholate and deoxycholate have been noted. Fluorescence polarisation studies of 1,6-diphenyl-1,3,5-hexatriene solubilised in bile salt micelles suggest a higher microviscosity for the interior of the deoxycholate micelle as compared to cholate. 1H NMR studies of deoxycholate over the range 1–100 mg/ml suggest that micelle formation leads to a greater immobilisation of the C18 and C19 methyl groups as compared to the C21 methyl group. Well resolved 13C resonances are observed for all three steroids even at high concentration. Both fluorescence and NMR studies confirm that dehydrocholate does not aggregate.
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The biosynthesis of certain amines in Lathyrus sativus seedlings was studied in isolated shoots and cotyledons. In shoots, arginine was about 14 times more efficient than ornithine for the synthesis of agmatine, putrescine, spermidine and spermine. Isotope dilution experiments, and the changes in specific activities of the 4 amines with time when 14C-arginine served as the precursor, indicated that putrescine and the polyamines were formed mainly from arginine, via agmatine. Similar experiments showed that cadaverine was formed at least in part from homoarginine, though lysine was ca 4 times more effective as a precursor. The pattern of changes in specific activity of homoagmatine and cadaverine with time when 14C-homoarginine served as the precursor support the conclusion that homoarginine and arginine follow analogous metabolic routes in the biosynthesis of putrescine and cadaverine respectively.
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In growing Lathyrus sativus seedlings, the levels of DNA, RNA and protein markedly decreased in the cotyledons and progressively increased in the embryo-axis. In cotyledons, spermidine and spermine contents were substantially reduced while those of agmatine and putrescine were sharply increased. By contrast the embryo-axis progressively accumulated relatively larger amounts of agmatine, homoagmatine. putrescine, cadaverine, spermidine and spermine in parallel with similar changes in its DNA, RNA and protein content. While the cotyledons contained ca 50% of the total agmatine and putrescine present in the plant embryo by day 10, the embryo-axis, though representing less than 20% of the dry wt, contained 90 and 75% of total cadaverine and homoagmatine respectively of the seedlings. Spermidine and spermine levels of this tissue were also comparatively higher, being of the order of 80 and 50% respectively of the total. The root and shoot portions of the embryo-axis also exhibited a similar relationship between changes in DNA, RNA and protein and all the above amines during development. However, the polyamine content of the shoots was relatively higher than those of the roots during the growth period.
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The fluorescent probe dansyl cadaverine has been shown to bind strongly to mixed bile salt-phospholipid micelles containing unsaturation in the fatty acyl chains. Incorporation of cholesterol into the mixed micelles reduces the number of molecules of bound dansyl cadaverine without altering the binding affinity. These results suggest a tighter packing of the hydrocarbon matrix of the micelles in the presence of cholesterol.
Resumo:
The fluorescent probe dansyl cadaverine has been shown to bind strongly to mixed bile salt-phospholipid micelles containing unsaturation in the fatty acyl chains. Incorporation of cholesterol into the mixed micelles reduces the number of molecules of bound dansyl cadaverine without altering the binding affinity. These results suggest a tighter packing of the hydrocarbon matrix of the micelles in the presence of cholesterol.
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The polyamines spermine, spermidine, putrescine, cadaverine, etc. have been implicated in a variety of cellular functions. However, details of their mode of interaction with other ubiquitous biomolecules is not known. We have solved a few structures of polyamine-amino acid complexes to understand the nature and mode of their interactions. Here we report the structure of a complex of putrescine with DL-glutamic acid. Comparison of the structure with the structure of putrescine-L-glutamic acid complex reveals the high degree of similarity in the mode of interaction in the two complexes. Despite the presence of a centre of symmetry in the present case, the arrangement of molecules is strikingly similar to the L-glutamic acid complex.
Resumo:
The polyamines spermine, spermidine, putrescine, cadaverine, etc. have been implicated in a variety of cellular functions. However, details of their mode of interaction with other ubiquitous biomolecules is not known. We have solved a few structures of polyamine-amino acid complexes to understand the nature and mode of their interactions. Here we report the structure of a complex of putrescine with DL-glutamic acid. Comparison of the structure with the structure of putrescine-L-glutamic acid complex reveals the high degree of similarity in the mode of interaction in the two complexes. Despite the presence of a centre of symmetry in the present case, the arrangement of molecules is strikingly similar to the L-glutamic acid complex.
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Capillary electrophoresis (CE) with tris(2,2'-bipyridyl) ruthenium (II) (Ru(bpy)(3)(2+)) electrochemiluminescence (ECL) detection technique was developed for the analysis of four polyamines (putrescine (Put), cadaverine (Cad), spermidine (Spd), and spermine (Spm)) analysis. The four polyamines contain different amine groups, which have different ECL activity. There are several parameters which influence the resolution and ECL peak intensities, including the buffer pH and concentrations, separation voltage, sample injection, electrode materials, and Ru(bpy)(3)(2+) concentrations. Polyamines are separated by capillary zone electrophoresis in an uncoated fused-silica capillary (50 cm x 25 mum (ID) filled with acidic phosphate buffer (200 mmol/L phosphate, pH 2.0) - 1 mol/L phosphoric acid (9:1 v/v) and a separation voltage of 5 kV (25 muA), with end-column Ru(bpy)(3)(2+) ECL detection. A 5 mmol/L Ru(bpy)(3)(2+) solution plus 200 mmol/L phosphate buffer (pH 11.0) is added into the reagent reservoir. The calibration curve is linear over a concentration range of two or three orders of magnitude for the polyamines. The analysis time is less than 25 min. Detection limits for Put and Cad are 1.9 x 10(-7) mol/L and 7.6 x 10(-9) mol/L for Spd and Spm, respectively.
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The biogenic amines, putrescine, cadaverine, spermidine and spermine were separated and quantified by capillary electrophoresis with pulsed amperometric detection. Detection potential of the pulsed amperometric detection was optimized as 0.6 V Optimal separation of the biogenic amines was achieved using a separation buffer of 30 mM citrate at pH 3.5, while keeping the buffer in the detection cell as 20 mM NaOH. Using these conditions, the four biogenic amines were baseline separated. Extrapolated limits of detection for putrescine, cadaverime, spermidine and spermine were 400, 200, 100 and 400 nM for the standard mixture (polyamines dissolved in running buffer), respectively. These are lower than ultraviolet detection and comparable or even lower than laser-induced fluorescence detection results as reported in the literature. The number of theoretical plates was maintained at the 105 level, which is absolutely higher than any reported method. When applying capillary electrophoresis-pulsed amperometric detection to milk analysis, only spermidine was found in amounts varying between 0.1 and 0.5 mg/kg.
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The influence of four levels (25, 50, 75 and 100%) of Class A pan evaporation replenishment (PER) on the marketable yield and bioactive amine content of American lettuce (Lactuca sativa cv Lucy Brown) grown under greenhouse conditions and drip irrigation was investigated. Lettuce was planted in 1.20 m x 2.10 m plots in a completely randomised block design with three replications. Lowest fresh head weights and diameters were obtained at 25% PER. Highest marketable yields and fresh head weights were obtained at 100% PER; however, no significant difference was observed when using 75% PER. The fresh head diameter was smaller only when using 25% PER. Four amines were detected in lettuce grown under 100% PER, with a total content of 7.60 mg kg(-1). Spermidine was the prevalent amine, followed by putrescine, cadaverine and agmatine. Higher spermidine and cadaverine levels were observed in the outer layers of leaves than in the intermediate and inner leaves. The contents of every amine except agmatine increased with water stress; however, a significant difference was observed only between 100 and 25% PER. The concentrations of accumulated putrescine were not capable of negatively affecting the sensory quality of the lettuce. (c) 2005 Society of Chemical Industry.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)