Gly m Bd 30 K (Soybean Vacuolar Protein)

6.5 Properties of Soybean Vacuolar Protein (Gly m Bd 30 K)

6.5.1 Molecular Biological Properties

Soybean Vacuolar Protein References

Allergen Nomenclature Gly m Bd 30 K (1) Ogawa et al. 1991

Molecular Mass
monomer: 34 kDa (1)*, 32 kDa (2)*, 30 kDa (SDS-PAGE) (3)
oligomer: 3000 kDa (Gel filtration) (2)
precursor: 46-47 kDa (1, 4)
*34 kDa polypeptide is processed during seedling growth to a 32 kDa polypeptide by the removal of an N-terminal decapeptide (1) (1) Kalinski et al. 1990, 1992
(2) Ogawa et al. 1993
(3) Helm et al. 1998
(4) Ji et al. 1998

Isoelectric Point pI 4.5 (oligomer)
(1) Ogawa et al. 1993

Amino Acid Sequence, mRNA, and cDNA

Proteins Gly m Bd 30K* P34*

SWISS-PROT: P22895

TrEMBL: O64458

GenBank: AB013289 J05560

Amino Acids 379 (2) 379 (1)

mRNA precursor 1287 bp (1)

cDNA precursor 6675 bp (2)

* Gly m Bd 30K and P34 are identical (Ogawa et al. 1995) (1) Kalinski et al. 1990, 1992
(2) Takano et al. 1995

recombinant Protein
Expression in insect cells:
46-, 34-, and 32-kDa forms (1) (1) Ji et al. 1998

Posttranslational Modifications
Glycosylation:
Carbohydrate composition: Man, GlcNAc, Fuc, and Xyl (3:2:1:1, molar ratio) (1)
N-Glycosylation site: Asn-170 (mature protein) (1) (1) Bando et al. 1996

Biological Function
serin protease (papain superfamily) (1) Kalinski et al. 1992

Sequence Homology
Der p 1, a house dust mite allergen: 30% identity (1), 54% similarity (2) (1) Ogawa et al. 1993
(2) Helm et al. 1998

Localization
Seed protein storage vacuoles in soybean cotyledons (electron microscopic immunolocalization, mAb (1, 2), patients' IgE (2)) (1) Kalinski et al. 1992
(2) Helm et al. 1998

Other Properties
Binding to alpha'- and alpha-subunits of beta-conglycinin (1)
Binding of syringolides (which trigger defense responses) (2) (1) Samoto et al. 1996
(2) Ji et al. 1998

6.5.2 Allergenic Properties

Soybean Vacuolar Protein References

Frequency of Sensitization
IgE-binding to Gly m Bd 30K in 65% of patients (1) (1) see 6.1 Sensitization to Soybean Allergens

B-Cell Epitopes
IgE binding sites located on (the precursor sequence):
aa 3-12 (synthetic peptide) (a) (1)
aa 100-110 (synthetic peptide) (a) (1)
aa 229-238 (synthetic peptide) (a) (1)
aa 299-308 (synthetic peptide) (a) (1)
aa 331-340 (synthetic peptide) (a) (1)
(a) dot / immunoblot
(1) Helm et al. 1998

Alteration of Allergenicity
galactomannan treatment (Maillard reaction):
complete reduction of allergenicity (a) (1)
(a) dot / immunoblot
(1) Babiker et al. 1998

Soybean Vacuolar Protein	References
*Frequency of Sensitization* IgE-binding to Gly m Bd 30K in 65% of patients (1)	(1) see 6.1 Sensitization to Soybean Allergens
*B-Cell Epitopes* IgE binding sites located on (the precursor sequence): aa 3-12 (synthetic peptide) (a) (1) aa 100-110 (synthetic peptide) (a) (1) aa 229-238 (synthetic peptide) (a) (1) aa 299-308 (synthetic peptide) (a) (1) aa 331-340 (synthetic peptide) (a) (1) (a) dot / immunoblot	(1) Helm et al. 1998
*Alteration of Allergenicity* galactomannan treatment (Maillard reaction): complete reduction of allergenicity (a) (1) (a) dot / immunoblot	(1) Babiker et al. 1998