Molecular Strategies to Improve The Nutritional Quality of Legume Proteins
- 546 Downloads
Legume proteins are relatively deficient in the sulfur amino acids. Among the different strategies to increase the sulfur amino acid contents of legumes, we have chosen to increase the biosynthesis of endogenous, non-abundant sulfur-rich proteins we have identified in soybean seed. We identified and isolated an 8 kDa sulfur-rich protein from the albumin fraction of soybean seed. Subsequently, a cDNA designated Gm2S-l, has been isolated and characterized. The Gm2S-l cDNA encodes a pre-proprotein that contains a signal peptide and a precursor protein that undergoes post-translational processing to yield the mature 8 kDa protein containing 7.8% methionine and 7.8% cysteine. The Gm2S-l gene is an ideal candidate for overexpression to improve the nutritional quality of soybean and other legumes.
KeywordsEssential Amino Acid Nutritional Quality Soybean Seed Seed Storage Protein Methionine Residue
Unable to display preview. Download preview PDF.
- de Lumen, B.O.; Uchimiya, H. Molecular strategies to enhance the nutritional quality of legume protein: an update. AgBiotech. News and Information 1997, 9, 53N–58N.Google Scholar
- de Lumen, B.O.; Krenz, D.C.; Revilleza, MJ. Molecular strategies to improve the protein quality of legumes. Food Tech. 1997, 57, 67–70.Google Scholar
- FAO/WHO/UNU. Energy and protein requirements. WHO Tech Rep Ser No. 724, 1985, WHO Geneva, Switzerland.Google Scholar
- Galvez, A.F.; Revilleza, J.M.; de Lumen, B.O.; Krenz DC. Enhancing the biosynthesis of endogenuous methionine-rich proteins (MRP) to improve the protein quality of legumes via genetic engineering. Proceedings of Food for Health in the Pacific Rim. 3rd International Conference of Food Science and Technology. Oct 19–23, 1997.Google Scholar
- Galvez A.F.; Revilieza, J.M.; de Lumen, B.O. A novel methionine-rich protein from soybean (Glycine max) seed: Cloning and characterization of cDNA. (Accession No. AF005030) Plant Physiol. 1997, 114, 1567.Google Scholar
- Kyte, J.; Doolittle, R.F. A simple method for displaying the hydropathic character of a protein. J. Biol. Chem. 1982, 757, 105–132.Google Scholar
- Liener, I.E. Nutritional value of food protein products. In Soybeans: Chemistry and Technology Vol. I Proteins. Smith A.K. and Circle S.J. eds. AVI Publishing, Westport, CT 1978, pp 203–277.Google Scholar
- Molvig, L.; Tabe, L.M.; Eggum, B.O.; Moore, A.E.; Craig, S.; Spencer, D.; Higgins, T.J.V. Enhanced methionine levels and increased nutritive value of seeds of transgenic lupins (Lupinus angustifolius L.) expressing a sunflower seed albumin gene. Proc. Natl. Acad. Sci. USA 1997, 94, 8393–8398.PubMedCrossRefGoogle Scholar
- Nordlee, J.A.; Taylor, S.L.; Townsend, J.A.; Thomas, L.A.; Townsend, R. Investigations of the allergenicity of Brazil nut 2S seed storage protein in transgenic soybean. OECD Workshop on Evaluation of New Foods, 1994, Oriel College Oxford, UK.Google Scholar
- Saalbach, I.; Pickardt, T.; Machemehl, F.; Saalbach, G.; Schieder, O.; Muntz, K. A chimeric gene encoding the methionine-rich 2S albumin of the Brazil nut (Bertholettia excelsa H.B.K.) is stably expressed and inherited in transgenic grain legumes. Mol. Gen. Genet. 1994, 242, 226–236.PubMedCrossRefGoogle Scholar
- Townsend, J.A.; Thomas, L.A.; Kulsek, E.S.; Daywalt, M.J.; Winter, K.R.K.; Altenbàch, S.B. Improving the quality of seed proteins in soybean. Proceedings of the 4th Biennial Conference on Molecular and Cellular Biologv of Soybean. July 27–29, 1992, 1992 Iowa State University, Ames IA. p 4.Google Scholar