Boric Acid-induced Heterogeneity of Conalbumin by Starch-gel Electrophoresis

Abstract

MULTIPLE molecular forms of conalbumin¹, the iron-binding component of avian egg white, have been described by numerous investigators under a variety of experimental conditions. In the original purification of conalbumin, Longsworth et al.² identified two components, the relative proportions of which were dependent on pH. Afterwards, by starch-gel electrophoresis, Lush³ identified two, and occasionally three, iron-binding proteins in native egg white, as did Williams⁴ and Ogden et al.⁵. In each of these cases^3–5, the slower migrating of the two components was the more intense; in the latter investigations^4,5 a corresponding heterogeneity was observed in transferrin, the iron-binding protein in the serum of the animal. Thus, in the chicken, as in other species, including man⁶, primates⁷, cattle^8,9, bison¹⁰, horses¹¹, and mice¹², a single transferrin allele appears to determine the synthesis of more than one molecular species of transferrin. Ultracentrifugal investigations on purified cattle transferrins indicate that the multiple bovine components do not represent a polymer series¹³.