2S Methionine-rich Protein (sunflower seed allergen)

Allergen Data Collection: Sunflower Seed (Helianthus annuus)
Internet Symposium on Food Allergens 3(2):103-114 (2001) [http://www.food-allergens.de]

5.2 Properties of 2S-Methionine-rich Protein (SSA)

5.2.1 Molecular Biological Properties

2S-Methionine-rich Protein References

Allergen Nomenclature none

Molecular Mass

SDS-PAGE

mature protein 12 kDa (2)

immature protein 16-17 kDa (1)

(1) Kelly & Hefle 2000
(2) Kelly et al. 2000

Isoelectric Point

IEF-PAGE

mature protein pI 5.91 (1)

immature protein pI 5.35 (1)

(1) Kelly et al. 2000

Amino Acid Sequence, mRNA, and cDNA

SSA (precursor) SSA (mature protein)

SWISS-PROT: P23110

GenBank: X56686

PIR:

Amino acids 141 residues (1) 103 residues (1)

mRNA 600 bp (1)

cDNA

Gene

(1) Kortt et al. 1991

Posttranslational Modifications
Disulfide bonds:
4 intra-chain disulfide bonds (1) (1) Egorov et al. 1996

Biological Function
Family of 2S albumin seed storage proteins (1) (1) Kortt et al. 1991

Sequence Homology
2S-Methionine-rich from Brazil nut: 34% aa identity (1)
Conglutin-like protein from peanut (Ara h 2): 34% aa similarity (2) (1) Kortt et al. 1991
(2) Stanley et al. 1997

5.2.2 Allergenic Properties

2S-Methionine-rich Protein References

Frequency of Sensitization
IgE-binding to immature protein in 40% of patients (1) (1) see 7.1 Sensitization to Sunflower Seed Allergens

2S-Methionine-rich Protein	References
*Frequency of Sensitization* IgE-binding to immature protein in 40% of patients (1)	(1) see 7.1 Sensitization to Sunflower Seed Allergens