CMP-NANA

Acetyl-CoA ADP Ala AMP ATP BHK CC9C10 CHO CHSE CMP-NANA CoQ CoQH2 DNA acetyl-coenzyme A adenosine diphosphate alanine adenosine monophosphate adenosine triphosphate baby hamster kidney cell line hybridoma cell line Chinese hamster ovary cell line Chinook salmon embryo cell line cytosine monophosphate-N-acetylneuraminic acid coenzyme Q dihydroubiquinone deoxyribonucleic acid... 

Cytidine monophosphate-sialic acid synthetase (EC 2.7.7.43) catalyzes the activation of /V-acetylneuraminic acid (NANA) by CTP to form CMP-NANA. 

The HPLC assay method developed for this activity involves the separation of the three compounds NANA, CTP, and CMP-NANA. However, at the wavelength used for detection, only the last two are detected. 

Figure 9.77 HPLC chromatogram of a typical enzyme assay sample with NANA and CTP as substrates. Peaks A, CMP B, CMP-NANA. (From Petrie and Korytnyk, 1983.)...

N-Acetylneuraminic acid (derived from CMP-NANA) often forms g branches from the main chain. 

A. The carbohydrates present in glycoproteins are synthesized from UDP-sugars and CMP-NANA. 

A kidney particulate system has been described which in the presence of a suitable acceptor is capable of incorporating radioactive NANA from CMP NANA- K), into ganglioside (Kanfer et al., 1964). Asialo-Tay-Sachs ganglioside (ceramide-glu-gal-gal NAc) but not asialoganglioside (ceramide-glu-gal-gal NAc-gai) stimulated this incorporation. Also present in the... 

Hematoside in Hamster Cells. Hakomori and Murakami (1968) reported that the levels of hematoside, the only ganglioside in BHK, was reduced in spontaneous and Py-transformed BHK cells. Similar results were observed with BHK cells transformed by two strains of Rous sarcoma virus (RSV) (Hakomori et aL, 1968). The reduced hematoside content in at least the Py-BHK cells was attributed to decreased activity of lactosylceramide CMP-NANA sialyltransferase, reaction 1 in Figure... 

Lactosylceramide CMP-NANA sialyltransferase activity was assayed on whole ceU homogenates as described in Section II. 

Hematoside and Sialyltransferase in Newborn Rat Kidney Cells. Another transformed cell system that we have investigated has shown a positive correlation between expression of the transforming virus and glycolipid content. Newborn rat kidney cells (NRK) transformed by either the Kirsten isolate of murine sarcoma virus (Ki-MSV) or a temperature-sensitive mutant were analyzed for glycolipid composition. The major sialylglycolipid in NRK cells is Gm3 When the cells were grown at the permissive temperature for transformation (31°C), there was substantially less hematoside in both transformed lines than in the control cells (unpublished observation of P. H. Fishman, S. A. Aaron-son, and R. O. Brady). At the nonpermissive temperature (39 ), the cells transformed by the mutant had more hematoside than the control cells. Lactosylceramide CMP-NANA sialyltransferase activity was deter-... 

Sialyltransferase activities in normal and virally transformed mouse 3T3 cells have also been measured with specific endogenous acceptors (Bosmann, 1972a). The acceptors were prepared by incubating the intact cells with neuraminidase and then trypsin. The desialylated material released from the cells was used to measure sialyltransferase activity in crude detergent extracts of the cells. Cells transformed by MSV, RSV, or Py had more acceptor and transferase activity than normal 3T3 cells. Surface sialyltransferase activity as measured by the ability of intact cells to transfer sialic acid- C from CMP-NANA- C to undefined surface acceptors was also higher in the transformed lines (Bosmann, 1972 ). 

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