12 results on '"Brazil nut"'
Search Results
2. Cloning and sequence analysis of a cDNA encoding a Brazil nut protein exceptionally rich in methionine.
- Author
-
Altenbach, Susan, Pearson, Karen, Leung, Filomena, and Sun, Samuel
- Abstract
The primary amino acid sequence of an abundant methionine-rich seed protein found in Brazil nut ( Bertholletia excelsa H.B.K.) has been elucidated by protein sequencing and from the nucleotide sequence of cDNA clones. The 9 kDa subunit of this protein was found to contain 77 amino acids of which 14 were methionine (18%) and 6 were cysteine (8%). Over half of the methionine residues in this subunit are clustered in two regions of the polypeptide where they are interspersed with arginine residues. In one of these regions, methionine residues account for 5 out of 6 amino acids and four of these methionine residues are contiguous. The sequence data verifies that the Brazil nut sulfur-rich protein is synthesized as a precursor polypeptide that is considerably larger than either of the two subunits of the mature protein. Three proteolytic processing steps by which the encoded polypeptide is sequentially trimmed to the 9 kDa and 3 kDa subunit polypeptides have been correlated with the sequence information. In addition, we have found that the sulfur-rich protein from Brazil nut is homologous in its amino acid sequence to small water-soluble proteins found in two other oilseeds, castor bean ( Ricinus communis) and rapeseed ( Brassica napus). When the amino acid sequences of these three proteins are aligned to maximize homology, the arrangement of cysteine residues is conserved. However, the two subunits of the Brazil nut protein contain over 19% methionine whereas the homologous proteins from castor bean and rapeseed contain only 2.1% and 2.6% methionine, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 1987
- Full Text
- View/download PDF
3. Unexpectedly higher expression levels of a chimeric 2S albumin seed protein transgene from a tandem array construct.
- Author
-
Conceição, Alexandre, Vliet, Adri, and Krebbers, Enno
- Abstract
In wild-type Arabidopsis seeds the 2S albumin seed protein gene family members are differentially expressed. In this work it is shown that as predicted by the wild type situation, the at2S2 promoter is much more effective than that of the at2S1 gene in the expression of a transgene. However, unexpectedly high expression levels were obtained using a construct in which the transgene was present as a tandem duplication in the T-DNA. Neither in this case nor in homozygous plants with either construct was epigenetic silencing observed. While transgene mRNA levels were of the same order of magnitude as the endogenous at 2S2 gene, protein levels were much lower. [ABSTRACT FROM AUTHOR]
- Published
- 1994
- Full Text
- View/download PDF
4. Accumulation of a Brazil nut albumin in seeds of transgenic canola results in enhanced levels of seed protein methionine.
- Author
-
Altenbach, Susan, Kuo, Chiung-Chi, Staraci, Lisa, Pearson, Karen, Wainwright, Connie, Georgescu, Anca, and Townsend, Jeffrey
- Abstract
We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up to 33% more methionine. The precursor of the methionine-rich protein is processed correctly in the seeds, resulting in the appearance of the mature protein in the 2S protein fraction. The 2S methionine-rich protein accumulates in the transgenic seeds at the same time in development as the canola 11S seed proteins and disappears rapidly upon germination of the seed. The increase in methionine in the canola seed proteins should increase the value of canola meal which is used in animal feed formulations. [ABSTRACT FROM AUTHOR]
- Published
- 1992
- Full Text
- View/download PDF
5. Particle bombardment-mediated transient expression of a Brazil nut methionine-rich albumin in bean ( Phaseolus vulgaris L.).
- Author
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Aragao, Francisco, Grossi de Sa, Maria, Almeida, Eleonora, Gander, Eugen, and Rech, Elibio
- Abstract
Bean ( Phaseolus vulgaris L.) mature embryos were transformed using biolistic methods with a plasmid containing 2S albumin and β-glucuronidase structural sequences, both under the control of the 35S CaMV promoter. We have shown that chimaeric tissues could be obtained and that both structural sequences were expressed to similar levels. [ABSTRACT FROM AUTHOR]
- Published
- 1992
- Full Text
- View/download PDF
6. [Untitled]
- Author
-
Lynn W. Godfrey, Helen M. Tu, and Samuel S. M. Sun
- Subjects
Methionine ,fungi ,Mutant ,food and beverages ,Plant Science ,General Medicine ,Chimeric gene ,Genetically modified crops ,Biology ,Molecular biology ,food.food ,chemistry.chemical_compound ,food ,chemistry ,Complementary DNA ,Gene expression ,Botany ,Genetics ,Agronomy and Crop Science ,Peptide sequence ,Brazil nut - Abstract
A cDNA encoding the methionine-rich (19 mol% Met) protein in Brazil nut was placed under the regulation of CaMV 35S promoter and nopaline synthase terminator and introduced into the potato cultivar Russet Burbank via Agrobacterium-mediated transformation. To further enhance the Met content in the transgenic plants, chimeric genes containing four mutant constructs, BoxIa (with 5 additional Met), BoxIIa (2 additional Met), BoxIaIIa (7 additional Met), and BoxIIa2 (7 additional Met), were also generated by sequence modifications of the cDNA and transferred into potato. Analysis of the microtubers and leaves of the transgenic potato plants revealed, in general, with the exception of the BoxIIa2, the presence of mRNA transcripts of the expected size and the correctly processed Met-rich 9 kDa subunit polypeptides. The expression levels in the leaves among the various constructs and individual transgenic plants varied between
- Published
- 1998
7. Unexpectedly higher expression levels of a chimeric 2S albumin seed protein transgene from a tandem array construct
- Author
-
Alexandre da Silva Conceicao, Adri van Vliet, and Enno Krebbers
- Subjects
DNA, Bacterial ,Transcription, Genetic ,Recombinant Fusion Proteins ,Transgene ,Arabidopsis ,Plant Science ,Biology ,Methionine ,Transformation, Genetic ,food ,Gene Expression Regulation, Plant ,Genetics ,Nuts ,Gene family ,Gene ,Post-transcriptional regulation ,Plant Proteins ,Wild type ,General Medicine ,Plants, Genetically Modified ,biology.organism_classification ,Molecular biology ,food.food ,Protein Biosynthesis ,Seeds ,Tandem exon duplication ,Agronomy and Crop Science ,Brazil nut - Abstract
In wild-type Arabidopsis seeds the 2S albumin seed protein gene family members are differentially expressed. In this work it is shown that as predicted by the wild type situation, the at2S2 promoter is much more effective than that of the at2S1 gene in the expression of a transgene. However, unexpectedly high expression levels were obtained using a construct in which the transgene was present as a tandem duplication in the T-DNA. Neither in this case nor in homozygous plants with either construct was epigenetic silencing observed. While transgene mRNA levels were of the same order of magnitude as the endogenous at 2S2 gene, protein levels were much lower.
- Published
- 1994
8. Accumulation of a Brazil nut albumin in seeds of transgenic canola results in enhanced levels of seed protein methionine
- Author
-
Susan B. Altenbach, Connie Wainwright, Jeffrey Townsend, Karen W. Pearson, Anca Georgescu, Chiung-Chi Kuo, and Lisa C. Staraci
- Subjects
food.ingredient ,Recombinant Fusion Proteins ,Genetic Vectors ,Immunoblotting ,Colza oil ,Gene Expression ,Plant Science ,Genetically modified crops ,Biology ,chemistry.chemical_compound ,Methionine ,Transformation, Genetic ,food ,Botany ,Genetics ,Nuts ,Food science ,Canola ,Plant Proteins ,Albumin ,food and beverages ,General Medicine ,Plants, Genetically Modified ,food.food ,Transformation (genetics) ,chemistry ,Germination ,Seeds ,Agronomy and Crop Science ,Plasmids ,Brazil nut - Abstract
We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up to 33% more methionine. The precursor of the methionine-rich protein is processed correctly in the seeds, resulting in the appearance of the mature protein in the 2S protein fraction. The 2S methionine-rich protein accumulates in the transgenic seeds at the same time in development as the canola 11S seed proteins and disappears rapidly upon germination of the seed. The increase in methionine in the canola seed proteins should increase the value of canola meal which is used in animal feed formulations.
- Published
- 1992
9. Particle bombardment-mediated transient expression of a Brazil nut methionine-rich albumin in bean (Phaseolus vulgaris L.)
- Author
-
M F de Sa, Elionor Rita Pereira de Almeida, Elíbio L. Rech, Francisco J. L. Aragão, and Eugen Silvano Gander
- Subjects
Recombinant Fusion Proteins ,Blotting, Western ,Plant Science ,chemistry.chemical_compound ,food ,Plasmid ,Gene expression ,Botany ,Genetics ,Nuts ,Cloning, Molecular ,Polyacrylamide gel electrophoresis ,Plant Proteins ,Cloning ,Methionine ,Plants, Medicinal ,biology ,Albumin ,food and beverages ,Fabaceae ,General Medicine ,Antigens, Plant ,biology.organism_classification ,Molecular biology ,food.food ,chemistry ,Electrophoresis, Polyacrylamide Gel ,Phaseolus ,Agronomy and Crop Science ,Brazil nut ,2S Albumins, Plant - Abstract
Bean (Phaseolus vulgaris L.) mature embryos were transformed using biolistic methods with a plasmid containing 2S albumin and beta-glucuronidase structural sequences, both under the control of the 35S CaMV promoter. We have shown that chimaeric tissues could be obtained and that both structural sequences were expressed to similar levels.
- Published
- 1992
10. Isolation, characterization and expression of a gene coding for a 2S albumin from Bertholletia excelsa (Brazil nut)
- Author
-
K. O. Holmstroem, G. R. De Paiva, L. A. B. De Castro, F. S. Gander, Mauro Carneiro, and M. F. de Sá Grossi
- Subjects
Sequence analysis ,TATA box ,Molecular Sequence Data ,Plant Science ,Biology ,food ,Albumins ,Genetics ,Consensus sequence ,Nuts ,Amino Acid Sequence ,Cloning, Molecular ,Promoter Regions, Genetic ,Gene ,Palindromic sequence ,Plant Proteins ,Repetitive Sequences, Nucleic Acid ,Base Sequence ,Intron ,food and beverages ,General Medicine ,Allergens ,Antigens, Plant ,Blotting, Northern ,Molecular biology ,TATA Box ,food.food ,Introns ,Blotting, Southern ,Gene Expression Regulation ,Multigene Family ,Seeds ,Bertholletia ,Agronomy and Crop Science ,Sequence Alignment ,Brazil nut ,2S Albumins, Plant - Abstract
Two genes, BE2S1 and BE2S2, coding for methionine-rich albumins of Brazil nut (Bertholletia excelsa H.B.K.) have been cloned and their sequence determined. The genes are members of a multigene family and one of them, i.e. BE2S1, codes for one of the dominant 2S isoforms. Its expression is highly regulated during seed development and with respect to tissue specificity. Sequence analysis has shown that the genes contain one intron and that the promoter of BE2S1 shows a canonical TATA motif. The transcription initiation site is located 26 nucleotides downstream from the TATA box. Sequence comparison of the promoter regions of 2S genes from Brassica napus, Arabidopsis thaliana and B. excelsa revealed the presence of TGCA palindromic sequences that appear to be arranged in a 2S-specific manner.
- Published
- 1991
11. Enhancement of the methionine content of seed proteins by the expression of a chimeric gene encoding a methionine-rich protein in transgenic plants
- Author
-
Samuel S. M. Sun, Gabrielle Meeker, Susan B. Altenbach, Karen W. Pearson, and Lisa C. Staraci
- Subjects
Nicotiana tabacum ,Genetic Vectors ,Gene Expression ,Plant Science ,Chimeric gene ,Transfection ,chemistry.chemical_compound ,food ,Methionine ,Gene expression ,HSPA2 ,Genetics ,Amino Acids ,Gene ,Plant Proteins ,chemistry.chemical_classification ,biology ,food and beverages ,General Medicine ,Plants ,biology.organism_classification ,food.food ,Recombinant Proteins ,Amino acid ,chemistry ,Biochemistry ,Agronomy and Crop Science ,Nutritive Value ,Brazil nut - Abstract
We have constructed a chimeric gene encoding a Brazil nut methionine-rich seed protein which contains 18% methionine. This gene has been transferred to tobacco and expressed in the developing seeds. Tobacco seeds are able to process the methionine-rich protein efficiently from a larger precursor polypeptide of 17 kDa to the 9 kDa and 3 kDa subunits of the mature protein, a procedure which involves three proteolytic cleavage steps in the Brazil nut seed. The accumulation of the methionine-rich protein in the seeds of tobacco results in a significant increase (30%) in the levels of the methionine in the seed proteins of the transgenic plants. Our data indicate that the introduction of a chimeric gene encoding a methionine-rich seed protein into crop plants, particularly legumes whose seeds are deficient in the essential sulfur-containing amino acids, represents a feasible method for improving the nutritional quality of seed proteins.
- Published
- 1989
12. Cloning and sequence analysis of a cDNA encoding a Brazil nut protein exceptionally rich in methionine
- Author
-
Karen W. Pearson, Samuel S. M. Sun, Filomena W. Leung, and Susan B. Altenbach
- Subjects
chemistry.chemical_classification ,Methionine ,Sequence analysis ,Protein subunit ,Protein primary structure ,food and beverages ,Plant Science ,General Medicine ,Biology ,food.food ,Amino acid ,chemistry.chemical_compound ,food ,Biochemistry ,chemistry ,Genetics ,Agronomy and Crop Science ,Peptide sequence ,Cysteine ,Brazil nut - Abstract
The primary amino acid sequence of an abundant methionine-rich seed protein found in Brazil nut (Bertholletia excelsa H.B.K.) has been elucidated by protein sequencing and from the nucleotide sequence of cDNA clones. The 9 kDa subunit of this protein was found to contain 77 amino acids of which 14 were methionine (18%) and 6 were cysteine (8%). Over half of the methionine residues in this subunit are clustered in two regions of the polypeptide where they are interspersed with arginine residues. In one of these regions, methionine residues account for 5 out of 6 amino acids and four of these methionine residues are contiguous. The sequence data verifies that the Brazil nut sulfur-rich protein is synthesized as a precursor polypeptide that is considerably larger than either of the two subunits of the mature protein. Three proteolytic processing steps by which the encoded polypeptide is sequentially trimmed to the 9 kDa and 3 kDa subunit polypeptides have been correlated with the sequence information. In addition, we have found that the sulfur-rich protein from Brazil nut is homologous in its amino acid sequence to small water-soluble proteins found in two other oilseeds, castor bean (Ricinus communis) and rapeseed (Brassica napus). When the amino acid sequences of these three proteins are aligned to maximize homology, the arrangement of cysteine residues is conserved. However, the two subunits of the Brazil nut protein contain over 19% methionine whereas the homologous proteins from castor bean and rapeseed contain only 2.1% and 2.6% methionine, respectively.
- Published
- 1986
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