Wiktionary
phosvitin
n. A yolk protein that is important in sequestering calcium, iron, and other cations.
Wikipedia
Phosvitin
Phosvitin is one of the egg (commonly hen’s egg) yolk phosphoproteins known for being the most phosphorylated protein found in nature. Phosvitin isolation was first described by Mecham and Olcott in the year 1949