Ovotransferrin

Abstract

Under steroid control, the expression of the transferrin gene in the oviduct of birds leads to the synthesis of ovotransferrin (OTf). OTf (formerly conalbumin) is an egg white glycoprotein responsible for the transfer of ferric ions from the hen oviduct to the developing embryo. It belongs to the transferrin family and shows about 50% homology with mammalian transferrin and lactoferrin (Mazurier et al. 1983). This neutral glycoprotein is synthesized in the hen oviduct and deposited in the albumen fraction of eggs at a ratio of 12% of the total protein content. It has been demonstrated that OTf is capable of binding two Fe3+ ions per molecule with high affinity, thus delivering iron into host cells by membrane-bound specific receptors (Mason et al. 1996). There is also extensive evidence of an antimicrobial and antiviral effect of OTf (Antonini et al. 1977; Bullen et al. 1978; Valenti et al. 1981, 1982, 1983, 1985, 1986, 1987; Visca et al. 1990; Ibrahim et al. 1998, 2000; Giansanti et al. 2002, 2005) and its possession of therapeutic properties against acute enteritis in infants has also been demonstrated (Corda et al. 1983). Moreover, OTf can be used as a nutritional ingredient in iron-fortified products such as iron supplements, iron-fortified mixes for instant drinks, sport bars, protein supplements, and iron-fortified beverages. © Springer-Verlag Berlin Heidelberg 2007.