7.4 Properties of Ovotransferrin

7.4.1 Molecular Biological Properties
 

Ovotransferrin (OT)	References
Allergen Nomenclature  Gal d 3	(1) King et al. 1994
Isoallergens and Variants 5 isoforms with replacement of residues: 64 (A/V), 81 (V/I), 135 (R/W), 220-221 (Q/K-L/N), 667 (S/N) (1)	(1) SWISS-PROT: P01012
Molecular Mass Mr 77.3-77.7 kDa 4 isoforms by mass spectrometry (1)	(1) Awade et al. 1994
Isoelectric Point  pI 5.6 - 6.2 (1) iron-free form: pI 7.17, monoferric form: pI 6.68, 2 Fe/mol OT: pI 6.24 and pI 6.09 (cIEF) (2)	(1) Holen & Elsayed 1990 (2) Richards & Huang 1997
Amino Acid Sequence, mRNA, and cDNA Gal d 3   SWISS-PROT: P02789 GenBank: X02009, Y00407 PIR: A03262, TFCHE Amino acids 686 residues (1) mRNA 2376 bp (2) cDNA 11068 bp (3)	(1) Williams et al. 1982 (2) Jeltsch & Chambon 1982 (3) Jeltsch et al. 1987
recombinant OT expression in baby hamster kidney cells (1)	(1) Mason et al. 1996
3D-Structure monoferric N-terminal half-molecule (1)	(1) Dewan et al. 1993
Posttranslational Modifications Disulfide bonds: 12 disulfide bonds: 10-45, 115-197, 160-174, 171-182, 228-242, 348-380, 405-680, 421-643, 454-530, 478-671, 488-502, 499-513 (2) additional bonds: 20-36 / 358-371 / 570-584 (2) Glycosylation of OT: carbohydrate content: 2.6% of whole Mr (1) carbohydrate composition: 1.7% GlcNAc, 0.9% Man (1) 1 N-glycosylation site: 473 structures of glycans (mass spectrometry) (3) biantennary glycans (hydrazinolysis, methanolysis, methylation analysis and, 1H-NMR spectroscopy) (4)	(1) Robinson 1972 (2) Williams et al. 1982 (3) Yet et al. 1990 (4) Jacquinot et al. 1994
Biological Function iron transport:  domain I 1-332  domain II 342-686  active sites: iron binding 60 / 92, 191 / 250, 395 / 431, 524 / 592, anion bindung: 121 / 460 (1) antimicrobial activity (2)	(1) SWISS-PROT (2) Valenti et al. 1983

7.4.2 Allergenic Properties
 

Ovotransferrin (OT)	References
Frequency of Sensitization IgE-binding to OT in 22 to 94 % of patients (1)	(1) see 6.1 Sensitization to Egg White Allergens