title: The diurnal rhythm of liver glycogen phosphorylase: correlating changes in enzyme activity and enzymic protein.
abstract: The diurnal rhythm of phosphorylase activity in mouse liver extracts was correlated with the 24 h fluctuations in phosphorylase protein. This last measurement was made using rocket immunoelectrophoresis. The peak activity of phosphorylase appeared coincident (at 18:00 h) with the greatest amount of phosphorylase protein detected. Conversely, the lowest activity measured and lowest enzymic protein content both occurred at 02:00 h. Regression analysis revealed a significant positive correlation between enzyme activity and protein. Thus changes in the cellular concentration of this enzyme are implicated in the diurnal rhythm of liver glycogen.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D007122:Immunoelectrophoresis; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D006005:Phosphorylases / Q000276:immunology / Q000378:metabolism*
chemical_list: D006005:Phosphorylases