The isoelectric fractionation of hen's-egg ovotransferrin.
1. Hen ovotransferrin was examined by isoelectric fractionation. 2. The major component observed in starch-gel electrophoresis can be isolated from the minor component. 3. When non-saturating amounts of iron are added to ovotransferrin, isoelectric fractionation demonstrates the existence of three molecular species corresponding to the metal-free protein, the one-iron-atom-protein complex and the two-iron-atoms-protein complex. 4. Isoelectric fractionation of human serum labelled with (59)Fe suggests that the transferrin of normal human serum also exists as metal-free protein, the one-iron-atom-protein complex and the two-iron-atoms-protein complex. 5. It is concluded that the binding constants for the first and second iron atoms are similar.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002645:Chickens; D004529:Egg White / Q000032:analysis*; D004586:Electrophoresis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D007503:Iron Isotopes; D013053:Spectrophotometry; D014168:Transferrin / Q000032:analysis*
D000596:Amino Acids; D007503:Iron Isotopes; D014168:Transferrin; D007501:Iron