Molecular weight and amino acid composition of glycinin subunits

Catsimpoolas, Nicholas; Kenney, J.; Meyer, Edwin W.; Szuhaj, Bernard F.

doi:10.1002/jsfa.2740220905

Cited by 72 publications

(44 citation statements)

References 12 publications

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“…The polypeptides are compactly folded, though considerable unstructured regions exist internally (Wolf, 1972). In both 7S and 11S globular structures, disulfide bonds also bind the polypeptide subunits together (Catsimpoolas et al, 1971;Koshiyama and Fukushima, 1976).…”

Section: Introductionmentioning

confidence: 97%

Mechanical and thermal properties of soy protein films processed by casting and compression

Guerrero

Retegi

Gabilondo

et al. 2010

Journal of Food Engineering

178

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Section: Introductionmentioning

confidence: 97%

Mechanical and thermal properties of soy protein films processed by casting and compression

Guerrero

Retegi

Gabilondo

et al. 2010

Journal of Food Engineering

178

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“…The oligomer consists of six subunits, each with a molecular mass of about 60 kD (Catsimpoolas et al, 1971). Assembly of glycinin oligomers begins in the endoplasmic reticulum of cotyledonary cells where 8s to 9 s trimers of the subunits are formed (Barton et al, 1982;Chrispeels et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

Effect of structural modifications on the assembly of a glycinin subunit.

et al. 1990

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A Gy, glycinin cDNA was modified and used to produce structurally altered 11s storage protein subunits. We evaluated these modified subunits for their ability to assemble into oligomers. Alterations made in the acidic polypeptide changed the subunit solubility characteristics but did not eliminate assembly. Modifications in the basic polypeptide usually eliminated assembly of subunits into trimers. A region exhibiting high natural variability located at the COOH terminus of the acidic polypeptide that we have designated the hypervariable region was also studied.Extensive deletions and insertions were tolerated in the hypervariable region without perturbing subunit assembly. Some of the insertions significantly increased the methionine content in the Gy, glycinin subunit. Together, our results indicated that the structure of the basic polypeptide was more critical for assembly of trimers than that of the acidic polypeptide, an observation that implies that the basic polypeptides direct trimer formation. The assembly assays described here will be useful in efforts to improve seed quality. Using them, the effects of modifications to the storage protein subunits can be rapidly evaluated before introducing the mutated genes into plants.

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“…The soybean 7S fraction consists of three major subunits, the a'-, a-, and a-subunits. (29,31); the lI S fraction, of two groups of subunits designated the acidic and basic subunits (5,19).…”

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confidence: 99%

Effects of Exogenous Methionine on Storage Protein Composition of Soybean Cotyledons Cultured In Vitro

Holowach

Thompson²,

Madison³

1984

Plant Physiol.

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ABSTRAC1Supplemental methionine in a complete culture medium increased the methionine content of the protein fraction of cultured soybean (Glycine max L. Merrill) cotyledons (Thompson, Madison, Muenster 1981 Phytochemistry 20: 941-945). To explain the observed increase in protein methionine, we have measured the amounts and subunit compositions of 7S and 11S storage proteins and determined the amino acid compositions of the three major protein fractions (2-5S, 7S, 11S) of seeds developed on plants and of cultured cotyledons grown in the presence or absence of supplemental L-methionine. Development of cultured cotyledons was representative of development of seeds on plants. The ratios of 11S to 7S proteins, the subunit contents, and amino acid compositions of their storage protein fractions were similar, but not identical. Supplemental methionine increased the mole percent methionine in each of the three protein fractions of cultured cotyledons and changed the amounts of several other amino acids. Supplemental methionine inhibited expression of the 7S a-subunit gene. Concomitant with the absence of the a-subunit, which contains no methionine, was an increase in the ratio of 11S to 7S proteins, and an increase in the methionine content of the subunits composing these fractions. Inhibition of 6-subunit gene expression by methionine in cultured cotyledons provides a reproducible, easily controlled system for the study of eucaryotic gene expression.Soybean seed proteins lack sufficient quantities ofsulfur amino acids to satisfactorily meet the dietary requirements of some monogastric animals. In this respect, soybeans are typical legume seeds. Soybeans, however, accumulate about twice as much protein in their seeds as other legumes, and up to four times as much protein as grain seeds. The nutritional quality of soybean and other legume seeds could be improved by raising the sulfurcontaining amino acid content of their proteins (37). Since the 7S and Il S storage protein fractions constitute about 70% of total seed protein, they have been the focus of efforts to raise protein methionine content. The soybean 7S fraction consists of three major subunits, the a'-, a-, and a-subunits. (29,31) In vitro experiments were designed so that sets of 5 to 46 cotyledon pairs were subjected to control and experimental treatments. Individual seeds were divided so that one-half was placed in complete medium lacking methionine, and the other half in complete medium containing 8.4 mm L-methionine.Rates of growth and protein accumulation were variable in seeds grown on plants. Seeds matured more slowly in the winter than in the summer. Maturity was therefore measured by increments of seed fresh weight, which was found to be a more consistent measure of the time course of development than days after flowering (13,18

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Molecular weight and amino acid composition of glycinin subunits

Cited by 72 publications

References 12 publications

Mechanical and thermal properties of soy protein films processed by casting and compression

Mechanical and thermal properties of soy protein films processed by casting and compression

Effect of structural modifications on the assembly of a glycinin subunit.

Effects of Exogenous Methionine on Storage Protein Composition of Soybean Cotyledons Cultured In Vitro

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