Brazil nut (Bertholletia excelsa HBK) proteins: fractionation, composition, and identification of a sulfur-rich protein

Sun, Samuel S. M.; Leung, Filomena W.; Tomic, Jody C.

doi:10.1021/jf00074a016

Cited by 65 publications

(69 citation statements)

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“…In addition, the presence of effective sinks must be engineered (e.g. Lys-rich [Sun et al, 1999] or Met-rich [Sun et al, 1987]) seed storage proteins) to entrap these essential amino acids. The impact of such alteration of nitrogen status on the composition of other vital metabolic components should also be analyzed.…”

Section: Discussionmentioning

confidence: 99%

“…The mean for each data point was calculated from a total of six to eight samples. Seed-soluble proteins were extracted as described previously (Sun et al, 1987). Each aliquot of 500 thoroughly air-dried seeds was first weighed using the AD-4 Autobalance (accuracy down to the microgram level; Perkin Elmer, Norwalk, CT) before being ground in 1 mL of seed extraction buffer (0.25 m sodium chloride and 0.05 m potassium phosphate [pH 7.0]) using mortar and pestle.…”

Section: Determination Of Soluble Seed Protein Contentsmentioning

confidence: 99%

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Overexpression of the ASN1 Gene Enhances Nitrogen Status in Seeds of Arabidopsis

et al. 2003

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In wild-type Arabidopsis, levels of ASN1 mRNA and asparagine (Asn) are tightly regulated by environmental factors and metabolites. Because Asn serves as an important nitrogen storage and transport compound used to allocate nitrogen resources between source and sink organs, we tested whether overexpression of the major expressed gene for Asn synthetase, ASN1, would lead to changes in nitrogen status in the ultimate storage organ for metabolites-seeds. Transgenic Arabidopsis constitutively overexpressing ASN1 under the cauliflower mosaic virus 35S promoter were constructed (35S-ASN1). In seeds of the 35S-ASN1 lines, three observations support the notion that the nitrogen status was enhanced: (a) elevations of soluble seed protein contents, (b) elevations of total protein contents from acid-hydrolyzed seeds, and (c) higher tolerance of young seedlings when grown on nitrogen-limiting media. Besides quantitative differences, changes in the relative composition of the seed amino acid were also observed. The change in seed nitrogen status was accompanied by an increase of total free amino acids (mainly Asn) allocated to flowers and developing siliques. In 35S-ASN1 lines, sink tissues such as flowers and developing siliques exhibit a higher level of free Asn than source tissues such as leaves and stems, despite significantly higher levels of ASN1 mRNA observed in the source tissues. This was at least partially due to an enhanced transport of Asn from source to sink via the phloem, as demonstrated by the increased levels of Asn in phloem exudates of the 35S-ASN1 plants.In higher plants, nitrogen is acquired from the environment via nitrate reduction (Crawford and Arst, 1993), ammonia uptake, or nitrogen fixation (Burris and Roberts, 1993). All inorganic nitrogen must first be reduced to ammonia by the action of nitrate and nitrite reductase before being assimilated into amino acids Miflin and Lea, 1980;Lea et al., 1990). In plants, the majority of ammonia is assimilated into organic form via the combined action of Gln synthetase and Gln 2-oxoglutarate aminotransferase. The products of Gln synthetase-Gln 2-oxoglutarate aminotransferase cycle, Gln, and Glu are highly reactive and are used in various anabolic pathways. Through the action of Asn synthetase (AS; EC 6.3.5.4), Gln will react with Asp to form Asn and Glu. Because all the substrates and products of the AS-catalyzed reaction are major nitrogen carriers in plant metabolism for transporting nitrogen in the phloem, the AS enzyme is believed to play an important role in regulating the flow of nitrogen into the organic nitrogen pool (Lam et al., 1994). Asn is an especially important nitrogen transport amino acid because it has a high nitrogen to carbon ratio (relative to the other amide amino acid Gln) and is relatively inert compared with the other nitrogen-transporting amino acids (Glu, Asp, and Gln). Therefore, Asn can be used for long-range nitrogen transport and storage, which is vital to physiological processes such as germination and nitrogen assimilation Siecie...

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Section: Discussionmentioning

confidence: 99%

Section: Determination Of Soluble Seed Protein Contentsmentioning

confidence: 99%

Overexpression of the ASN1 Gene Enhances Nitrogen Status in Seeds of Arabidopsis

et al. 2003

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“…32,37,38 The metal ions present high-affinity for these kinds of amino acids. For Brazil-nut, all analytes are mainly in albumin, globulin and glutelin fractions.…”

Section: Cu Fe Mn and Zn Distribution In Each Fractionmentioning

confidence: 99%

Cu, Fe, Mn and Zn distribution in protein fractions of Brazil-nut, cupuassu seed and coconut pulp by solid-liquid extraction and electrothermal atomic absorption spectrometry

Naozuka¹,

Oliveira²

2007

J. Braz. Chem. Soc.

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Neste trabalho foram determinados Cu, Fe, Mn and Zn em extratos de castanha-do-Pará (Bertholletia excelsa), semente de cupuaçu (Theobroma grandiflorum) e polpa de coco (Cocos nucifera) usando extração sólido-líquido e espectrometria de absorção atômica com atomização eletrotérmica. Foram empregadas diferentes soluções extratoras (mistura de metanol e clorofórmio 1:2 v/v, água, 0,5 mol L -1 NaCl, 70% v/v etanol e 0,5 mol L -1 NaOH) para extração de lipídios, albuminas, globulinas, prolaminas e glutelinas, respectivamente. As concentrações de proteínas encontradas na castanha-do-pará foram maiores do que aquelas encontradas na semente de cupuaçu e polpa de coco. Nas frações lipídicas foram encontradas maiores concentrações de Fe em castanhado-pará e semente de cupuaçu e Zn em polpa de coco. As determinações dos elementos nos extratos proteicos de castanha-do-pará indicaram que eles estão ligados, preferencialmente, às albuminas, globulinas e glutelinas. O mesmo comportamento não foi observado para semente de cupuaçu e polpa de coco. As concetrações dos elementos variaram para os diferentes extratos proteícos. Em geral, as maiores concentrações de proteínas foram determinadas nos extratos em NaOH. Por outro lado, as menores concentrações de Cu, Fe, Mn e Zn foram encontradas nessa fração.In this work Cu, Fe, Mn and Zn were determined in extracts of Brazil-nut (Bertholletia excelsa), cupuassu (Theobroma grandiflorum) seeds and coconut (Cocos nucifera) pulp, using solid-liquid extraction and electrothermal atomic absorption spectrometry. Different extractant solutions (mixture of methanol and chloroform 1:2 v/v, water, 0.5 mol L -1 NaCl, 70% v/v ethanol, and 0.5 mol L -1 NaOH) were used for extracting lipids, albumins, globulins, prolamins and glutelins, respectively. The protein concentrations determined in Brazil-nut are higher than those observed for cupuassu and coconut pulp. The analysis of lipid fractions reveals high concentations of Fe in Brazil-nut and cupuassu seed and Zn in coconut pulp. For Brazil-nut, these elements are mainly associated to albumin, globulin and glutelin fractions. The same behaviour was not observed for cupuassu seed and coconut pulp. The element concentrations changed in each protein fraction. In general, high concentrations of proteins were determined in NaOH extractants. On the other hand, low concentration of Cu, Fe, Mn and Zn were found in this fraction.Keywords: solid-liquid extraction, electrothermal atomic absorption spectrometry, Brazilnut, cupuassu, coconut IntroductionFoods are one of the main sources of metals for human body. Most of the metal ions present in foods are bound to specific proteins or enzymes and exert their effects as active or structural centers, command process such as catalysts, substrate binding and activation, transportation and storage. 1,2 In this way, the knowledge of the foods compositional, nutritional and functional properties is fundamental for defining their quality. In general, nutritional properties are characterized by both the abundance and bio...

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“…Information on fractionation and characterization of Brazil nut kernel proteins [21], methionine rich 2S fraction [24] and N-terminal amino acids of 7S fraction [3] and functional properties of protein isolate and concentrate [6] are available. However, there seems a lack of data on the functionality of chemically modified Brazil nut kernel globulin in scientific literature.…”

Section: -Introductionmentioning

confidence: 99%

Functional characterization of acetylated Brazil nut (Bertholletia excelsa HBK) kernel globulin

Ramos¹,

Bora²

2004

Ciênc. Tecnol. Aliment.

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Brazil nut (Bertholletia excelsa HBK) proteins: fractionation, composition, and identification of a sulfur-rich protein

Cited by 65 publications

References 3 publications

Overexpression of the ASN1 Gene Enhances Nitrogen Status in Seeds of Arabidopsis

Overexpression of the ASN1 Gene Enhances Nitrogen Status in Seeds of Arabidopsis

Cu, Fe, Mn and Zn distribution in protein fractions of Brazil-nut, cupuassu seed and coconut pulp by solid-liquid extraction and electrothermal atomic absorption spectrometry

Functional characterization of acetylated Brazil nut (Bertholletia excelsa HBK) kernel globulin

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