ABSTRACT
This chapter summarizes the information on three structurally and functionally different globular proteins of egg white proteins to help establishing structure-function relations and to clarify possible roles for their existence in the hen egg. One of them is an intriguing protein with unknown biological function (ovalbumin), another is an iron-binding protein with unclear antimicrobial properties (ovotransferrin), and the third is a bacteriolytic protein (lysozyme) with well-characterized physicochemical properties. Treatment of ovalbumin with subtilisin under defined conditions releases a hexapeptide at the residue 358, leaving two peptide chains strongly bound by noncovalent bonds. Ovalbumin is known to form a transparent standing gel upon heating for gelation, the characteristics of the organized thread of beads' macromolecular interactions. The chapter compares the amino acid sequences of ovotransferrin and lactoferrin. The significant structural similarities between lactoferrin and ovotransferrin justify the similarity of their biological roles, implication in the transport of iron in a soluble form to the target cells.
