PROPERTIES OF GLYCOGEN PHOSPHORYLASE BEFORE AND AFTER FERTILIZATION IN SEA URCHIN EGGS

Glycogen phosphorylase was studied in unfertilized and fertilized sea urchin eggs, in attempts to understand the mechanism of the activation of carbohydrate metabolism caused by fertilization. The enzyme was found mostly in the active form and quantitative differences were not observed between its activity in the unfertilized eggs and in embryos at different stages of development. The localization of the enzyme within the cell was investigated and the results reported seem to indicate that the activation of phosphorylase involves its release from a subcellular structure, which binds the enzyme in the unfertilized egg. © 1968.