6.6.1 Molecular Biological Properties
Glycinin | References | ||||||||||||||||||||||||||||||||||||
Allergen Nomenclature none | |||||||||||||||||||||||||||||||||||||
Molecular Mass
320-360 kDa (SEC)
6 subunits: 58-62 kDa each subunit: acidic polypeptide 31-45 kDa, basic polypetide 18-20 kDa exception: acidic subunit A5 10 kDa |
(1) Brooks & Morr 1985 | ||||||||||||||||||||||||||||||||||||
Isoelectric
Point acidic subunits pI 4.8-5.5, basic subunits
pI 6.5-8.5 (IEF-PAGE, 2D-PAGE)
estimated values according to (1) and (2) |
(1) Staswick et al.
1981
(2) Lei & Reeck 1987 |
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Amino Acid Sequence,cDNA, and
mRNA
|
(1) Staswick et al. 1984a
(2) Fukazawa et al. 1985 (3) Momma et al. 1985 (4) Cho & Nielsen 1989 (5) Nielsen et al. 1989 |
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recombinant Protein
Expression in Escherichia coli: glycinin (A1aB1b and A2B1a) 57 kDa (1) glycinin (A1aB1b) with modified functional and nutritional properties (2) Expression in Yeast: site-directed mutagenesis of proglycinin (A1a,B1b) (3) |
(1) Fukazawa et al. 1985
(2) Kim et al. 1990 (3) Katsube et al. 1998 |
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3D-Structure
X-ray studies of recombinant proglycinin (1, 2) |
(1) Gidamis et al. 1994
(2) Utsumi et al. 1996 |
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Posttranslational Modifications
Disulfide bonds acidic and basic subunits linked by disulfide bond: A2 Cys-86 to B1a Cys-7 (1) Glycosylation: small glycosylated portion of glycinin (approx. 1%) (2) glycosylation of site-mutated proglycinin (4) Phosphorylation: in vitro phosphorylation of Ser-75 and Ser-117 (3) |
(1) Staswick et al.
1984b
(2) Lei & Reeck 1987 (3) Fouques et al. 1998 (4) Katsube et al. 1998 |
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Genetic Variants
at least 5 variants (see Amino Acid Sequence) (1) |
(1) Staswick et al. 1981 | ||||||||||||||||||||||||||||||||||||
Biological Function
Seed storage protein (11S fraction) |
6.6.2 Allergenic Properties
Glycinin | References |
Frequency of Sensitization
IgE-binding to glycinin in 90% of patients (1, 3) to 11S-fraction (1, 2),acidic- and basic-subunit (a) (2) to acidic-subunits (A1a, A1b, A2, A3, and A4) (b) (3) to acidic-subunit (a) (4) (a) immunoblot (b) EAST |
(1) see 6.1 Sensitization
to Soybean Allergens
(2) Burks et al. 1988 (3) Djurtoft et al. 1991 (4) Müller et al. 1998 |
B-Cell Epitopes
IgE-binding region on acidic chain from glycinin G1: aa 192-306 (GluC protease digest) (1) (a) SDS-PAGE / immunoblot |
(1) Zeece et al. 1999 |
Allergenic Potencies
higher IgE-binding to acidic-subunit A4 than to A1a, A1b, A2, and A3 (EAST) (1) |
(1) Djurtoft et al. 1991 |
Alteration of Allergenicity
heat treatment: soybeans cooked at 100°C for 2h: IgE-binding to stable acidic-subunit (immunoblot) (1) |
(1) Müller et al. 1998 |
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