7.4 Properties of Bovine Serum Albumin

7.4.1 Molecular Biological Properties
 

Bovine Serum Albumin (BSA)	References
Allergen Nomenclature  Bos d 6	(1) Larsen & Lowenstein 1999
Molecular Mass   Mr in SDS-PAGE: 67.0 kDa (1), 66.3 kDa (2)	(1) Miller et al. 1993 (2) Wal 1998
Isoelectric Point  pI 4.7-4.95 (1), 4.9-5.1 (2)	(1) Miller et al. 1993 (2) Wal 1998
Amino Acid Sequence, mRNA, and cDNA BSA   SWISS-PROT: P02769 GenBank: M73993, X58989, Y17769 PIR: ABBOS Amino acids 583 residues (1) mRNA 2035 bp, 2061 bp, 1883 bp cDNA	(1) Brown 1975
Posttranslational Modifications Disulfide Bridges: 9 disulfide bonds  (1)	(1) Brown 1974
Biological Function BSA belongs to the ALB/AFP/VDB family, main plasma protein (1) 3 homologous domains: I aa 4-177, II aa 196-369, III aa 388-567 (1) good binding capacity for water, Ca2+, Na+, K+, fatty acids, hormones, bilirubin and drugs, main function regulation of colloidal osmotic blood pressure (1)	(1) SWISS-PROT
Location production in plasma, extracellular secretion (1)	(1) SWISS-PROT
Sequence Homology serum albumin from sheep: aa sequence identity 92% (1) serum albumins from pig, cat, human, rhesus macaque, horse: aa sequence identities 74-79% (1)	(1) BLAST at PIR
Other Properties possible trigger of insulin-dependent diabetes mellitus: BSA peptide aa 126-144 (ABBOS) may be the reactive epitope (1)	(1) Karjalainen et al. 1992

7.4.2 Allergenic Properties
 

Bovine Serum Albumin (BSA)	References
Frequency of Sensitization IgE-binding to BSA in 0-88% of patients (1)	(1) see 7.1 Sensitization to Cow's Milk Allergens
Alteration of Allergenicity heat treatment: Negative reaction to cooked BSA (1.8 g) and positive reaction to uncooked BSA (55 mg) in DBPCFC in a 19-year old woman (2) pepsin hydrolysis: ABBOS epitope (aa 126-144) not completely eliminated during digestion at pH 3-4 (mAb ELISA inhibition)* (1) * no IgE-binding studies	(1) Alting et al. 1997 (2) Kanny et al. 1998