5.2.1 Molecular Biological Properties
 

14-16 kDa Rice Allergens	References
Allergen Nomenclature
Isoallergens and Variants At least 7 isoallergens of 14-16 kDa rice allergens which share > 67% amino acid sequence identity (2) fullfilling the definition of isoallergens of the WHO/IUIS Allergen Nomenclature Subcommittee (1)	(1) King et al. 1994 (2) Matsuda et al. 1996
Molecular Masses  14-16 kDa (SDS-PAGE) (1)	(1) Matsuda et al. 1991
Isoelectric Points pI 6-8 (1)	(1) Matsuda et al. 1991
Amino Acid Sequence,mRNA, and cDNA  Isoallergens RA14 (2) RA14B (3) RA14C (3) RA5 (2) RA5B (3) RA16 (3) SWISS-PROT: Q01882 Q01881 GenBank: D11432 D42139 D42140 D11430 D42142 D42141 PIR: S31080 S59922 S59923 S31078 S59925 S59924 Amino Acids 139 166 160 131 160 157 mRNA  precursor 618 bp 643 bp 606 bp 618 bp 631bp 631 bp cDNA precursor              Isoallergens RA17 (1, 2) RAG1 (2) RAG2 (2) RA138 (4) RA SWISS-PROT: Q01883 Q01884 Q01885     GenBank: D11431 D11433 D11434   AF042200 PIR: S21157 S31081 S31082   T02664 Amino Acids 135 1-95 * 140 133 157 mRNA  precursor 636 bp       709 bp cDNA precursor   1286 bp 1603 bp 477 bp    * partial sequence	(1) Izumi et al. 1992 (2) Adachi et al. 1993 (3) Alvarez et al. 1995a (4) Oh et al. 1998
cDNA library / recombinant Proteins cDNA library: cDNA clones from maturing (1, 3, 4) and developing (5) seeds encoding rice allergens Expression in Escherichia coli: Expression of 4 rice allergens (2)	(1) Adachi et al. 1993 (2) Alvarez et al. 1995b (3) Matsuda et al. 1996 (4) Nakamura & Matsuda 1996 (5) Oh et al. 1998
Posttranslational Modifications Disulfide bonds: 5 disulfide bonds (1)	(1) Nakase et al. 1998
3D-Structure 3D-Structure prediction of 16-kDa allergen: compactly folded protein, small hydrophobic core, rich in sheet and helix structures (1)	(1) Nakase et al. 1998
Biological Function alpha-amylase/trypsin inhibitor family (1) Inhibitory activity toward human salvary alpha- amylase, not to bacterial alpha- amylase (2)	(1) Alvarez et al. 1995a, b (2) Nakase et al. 1996
Sequence Homology 14-16 kDa Rice allergens: sequence identities DNA > 80%, aa > 70% (2, 3) Alpha-amylase / trypsin inhibitors from wheat and barley: DNA sequence identities 20-40% (1, 3, 4, 5) Alpha-amylase / trypsin inhibitor family: well conserved 10 cystein residues region (1, 3) Castor bean storage protein: (1) Lipid transfer proteins:  sequence of 25 C-terminal aa of 14-16 kDa rice allergen clones resembles plant lipid transfer proteins (2)	(1) Izumi et al. 1992 (2) Alvarez et al. 1995a (3) Matsuda et al. 1996 (4) Nakamura & Matsuda 1996 (5) Nakase et al. 1998
Localization Maturing rice seeds (2) Albumin / globulin protein fractions (1)	(1) Matsuda et al. 1991 (2) Matsuda et al. 1996

 5.2.2 Allergenic Properties
 

14-16 kDa Rice Allergens	References
Frequency of Sensitization IgE-binding to 14-16 kDa rice allergens in 67-100% of patients (1) IgE-binding to 14-16 kDa isoallergens (2): a) 14-15.5 kDa allergen in 64% b) RA14 (~16 kDa) gene family, 3 isolated fractions: 41% (for 1 fraction) and 29% (other 2 fractions)  c) RA17 (14-15.5 kDa) in 29% (17 rice allergic patients, RAST)	(1) see 6.1 Sensitization to Rice Allergens (2) Nakase et al. 1996