Bovine serum albumin is stabilised by 17 disulphide bridges. It is relatively stable and Xu & Ding (2004) [1488] in a purification used heat and isopropyl alcohol to denature and precipitate the other plasma proteins except for immunoglobins. However, heating at 75°C and above produces disulphide linked oligomers (Havea et al, 2000 [1492]).

Restani et al. (2004) [1478] review IgE binding data using sera from beef allergic patients. They note that reduction of the disulphides reduces but does not abolish IgE binding.

Beretta et al. (2001) [1484] reported that sequential epitopes were able to resist proteolysis for 60 min when BSA was digested in vitro with pepsin at the ratio of enzyme to substrate of 1:120 (w/w).

Serum albumin regulates the colloidal osmotic pressure of blood, binds several cations, and is the principal transporter of fatty acids, hormones and bilirubin that would be otherwise insoluble in plasma. In addition to being the most abundant plasma protein, a low level finds its way into milk.

Levi & Gonzalez Flecha (2002) [1486] argue that the dimer is non-covalent and need not involve a disulphide link. By contrast, Hunter & Carta (2001) [1487] suggest that the dimer is disuphide linked and can be removed by purification using BRX-Q as anion exchanger.

Neyestani et al. (2003) [1454] describe a low cost purification starting from whey after removal of casein from defatted milk using hydrochloric acid. Globulins were precipitated by 50% saturated ammonium sulfate. The supernatant was fractionated using ion-exchange on DEAE cellulose. Alpha-lactalbumin and bovine serum albumin co-eluted and were then isolated by Sephadex G-50 gel filtration.

Xu & Ding (2004) [1488] used heat and isopropyl alcohol to denature and precipitate the other plasma proteins and isolated bovine serum albumin and immunoglobins by chromatography on CM-Trisacryl with 98% and 96.8% purity respectively.

Natale et al. (2004) [1409] found that 45% of 20 sera from patients aged 4 months to 14 months with cow's milk allergy contained IgE against bovine serum albumin.

Martelli et al. (2002) [1479] reviews the link between cow's milk allergy and allergy to meats such as beef. Bovine serum albumin is an important common allergen. However, Werfel et al. (1997) [1626] suggest that its allergenicity is generally destroyed if beef is well cooked.

The 3-dimension structure of bovine serum albumin has not been determined. However, that of the homologue human serum albumin, with 76% identity, is available both free and complexed with many hydrophobic ligands with PDB code 1hk1.

Bovine serum albumin residues 126-144 (ABBOS) have been reported to be responsible for the autoimmune reaction directed against pancreatic islet cells causing diabetes (Karjalainen et al, 1992 [1481]). This remains controversial (Knip, 2003 [1483]; Persaud & Barranco-Mendoza, 2004 [1482]) but removal of this epitope as well as IgE binding is often an objective in producing infant formulas.

Anaphylaxis due to bovine serum albumin has also been reported in a patient injected with cells cultured in fetal calf serum (Mackensen et al, 2000 [1491]).