GLYCOGEN SYNTHESIS FROM URIDINE DIPHOSPHATE GLUCOSE: The Distribution of the Enzyme in Liver Cell Fractions

D. J. L. Luck
1961 Journal of Cell Biology  
The distribution in liver cell fractions of UDPG-glycogen transferasc has been studied. In fasting animals which have been refed 6 hours before sacrifice, the distribution of the enzyme in the various cell fractions can be correlated with the glycogen content of each fraction. A purified glycogen fraction has been prepared by differential centrifugation in sucrose gradients. This glycogen fraction contains vesicular structures which resemble those seen in association with glycogen deposits in
more » ... cogen deposits in the intact liver cell. In addition, the glycogen pellet contains UDPG-glycogen transferase in high specific activity. Subfractionation of the glycogen pellet separates the majority of vesicular elements from the bulk of transferase activity and glycogen. The evidence presented suggests that the presence of UPDG-glycogen transferase in the glycogen pellet is to be attributed to its binding to glycogen rather than to its association with the structural elements found in the glycogen fraction. Male Sprague-Dawley rats, 150 to 250 gm, obtained from the Holtzman Rat Co., were prepared 196
doi:10.1083/jcb.10.2.195 fatcat:bbuxnjgh3rgx7kk6v46csubwkq