Reversible Phosphate Transfer between Yolk Phosphoprotein and Adenosine Triphosphate

Preparations and MethodsPhosphoprotein was prepared from fresh egg yolk by the method of Mecham and Olcott (23); they introduced the name, phosvitin, which will be used here.The compound does not seem to be very different from that described as vitellic acid in earlier studies by Lipmann and Levene (5).Our present preparation contained 10% phosphorus, or 3.2 pmoles of phosphate per mg of protein.