Biosynthesis of proteins, nucleic acids and glycosphingolipids by synchronized KB cells

The biosynthesis of glycosphingolipids and various types of proteins and nucleic acids at specific periods of the cell cycle was studied by using synchronized KB cells. Maximum incorporation of radioactive galactose, leucine and thymidine into several proteins and nucleic acids occurred as has been reported previously (6,11). Maximum incorporation of D-1[¹⁴C] galactose into glycosphingolipids was observed during the M and G-1 phases. There was a 5 fold increase in the levels of gangliosides and combined neutral glycosphingolipids during the M and G-1 phases. Thus, regulated biosynthesis of glycosphingolipids and macromolecules might be important in the cyclic expression of some of the functional properties which are characteristic of these compounds.