ABSTRACT
The study of enzymic activities found in hen eggs has become refined and steady in relation to the development of enzyme kinetics and protein chemistry. This chapter provides the enzymic activities found in unfertilized eggs. Two types of aminopeptidases, glutamylaminopeptidase and methionine-preferring aminopeptidase have been found in egg white. Nucleoside triphosphatases including ATPase have been found in vitelline membrane and egg white. Pyruvate kinase catalyzes the reaction from phospho enolpyruvate and ADP to pyruvate and ATP, and it plays one of the most important roles in the regulation of glycolysis. Egg yolk type M2 pyruvate kinase is phosphorylated by chicken oviduct-derived protein kinase. Wouters and Stockx found two Ribonucleases (RNase) activities in egg yolk and partially purified them by chromatography on hydroxyapatite and a glass bead column following the solubilization from yolk granules; most of the yolk RNase activities are associated with yolk granules.
