Time course of udp-gal: N-acetylglucosamine B- [1- -4] galactosyltransferase in homogenates of chinese hamster ovary cells at either

The effect of different temperatures and time of incubation on the activity of UDP-Gal: GlcNAC beta [1- ->4] galactosyltransferase were studied in this paper. The time course has been done on 150 mu l of cell sonicate of the Chinese Hamster Ovary cells [CHO cells], 2 mu l of UDP-[3H] galactose [2.5 mM.], 100 mu l of 50 mM. GlcNAC, and 50 mu l of assay mixture [500 mM. MnCl2, H2O, 10% triton X-100, 1.25 M. of galactonolactone, and 125 mM. ATP], at either temperature 20C or 37C. At each time, point zero, 30, 60 and 90 minutes, about 25 mu l from aliquot was removed and 1 ml of water was added in an Eppendorf tubes. Samples were boiled for 5 min to denature the enzyme, then all the samples were desalted by passing over a column of Dowax-Borate to isolate the product of N-acetyllactosamine. The degree of formation of this compound was dependent on the enzymatic activity of galactosyltransferase of CHO cells which is correlated with time and temperature. The product was diminished at 20C, while at 37C, the amount of this product was increased. Also, it was found in this study that the enzymatic activity of UDP-Gal: GlcNAC beta [1- >/4] galactosyltransferase in CHO cells was affected by temperature and was time-dependent

factors affecting the glycoproteins synthesized by embryonal carcinoma cell line F9 and the differentiated cells

To evaluate other factors important in the biosynthesis of the glycoproteins, the effect of low temperature 20C and 37C, and the time course of incubation of F9 cells and differentiated F9 cells media containing 6-3H-galactose, and in the other experiment in media containing 2-3H-mannose were examined. This study investigated the effect of 20C on the biosynthesis of glycoproteins in the mouse teratocarcinoma cell line. These cells were unusual in that upon treatment with 0.1 uM all-trans-retinoic acid the cells differentiate within 3 days to parietal endoderm-like cells and begin to synthesize basement membrane proteins, such as type IV collagen and laminin. In addition, the differentiated were cells no longer tumorigenic and synthesize different types of oligosaccharides on their glycoproteins than those that were made by undifferentiated F9 cells. Glycoproteins biosynthesis by either type was unaffected by low temperature treatment