Release of Glycosyltransferase and Glycosidase Activities from Normal and Transformed Cell Lines1
نویسندگان
چکیده
The release of galactosyltransferase, sialyltransferase, and several glycosidase activities into the growth media from sev eral normal and transformed cell lines was examined. Six of the seven cell lines released galactosyltransferase into their culture media. Only the human leukemia CCRF-CEM cells failed to release demonstrable galactosyltransferase activity. Release of galactosyltransferase activity into the media closely paralleled the growth curves for all but the BHKpy cells. These cells continued to release peak levels of galactosyltransferase activity into the culture media after their growth had plateaued. Media galactosyltransferase activity was unaffected by Triton X-100 treatment and remained in the supernatant fraction of a 100,000 x g, 12-hr centrifugation, suggesting that the cells release galactosyltransferase in a soluble form. In contrast to galactosyltransferase activity, only one of the cell lines (L1210) released sialyltransferase activity in appreciable amounts. Even this level of activity was 20-fold less than that observed for galactosyltransferase in the media from L1210 cells. Of the nine glycosidase activities assayed, only N-acetylglucosaminidase was observed in significant amounts in the media from all but the CCRF-CEM cells. However, W-acetylglucosaminidase release did not correlate closely with cell growth. These find ings suggest a relatively specific release of galactosyltransfer ase and A/-acetylglucosaminidase activities by cells in tissue culture. Moreover, the release of galactosyltransferase closely parallels cell growth. The significance of these released en zymes, especially to cell growth, has yet to be determined.
منابع مشابه
Release of glycosyltransferase and glycosidase activities from normal and transformed cell lines.
The release of galactosyltransferase, sialyltransferase, and several glycosidase activities into the growth media from several normal and transformed cell lines was examined. Six of the seven cell lines released galactosyltransferase into their culture media. Only the human leukemia CCRF-CEM cells failed to release demonstrable galactosyltransferase activity. Release of galactosyltransferase ac...
متن کاملCell surface glycolipid and glycoprotein glycosyltransferases of normal and transformed cells.
Normal and transformed mouse fibroblasts catalyze transfer of sialic acid, galactose, IV-acetylgalactosamine, N-acetylglucosamine, glucose, and mannose from nucleotide sugar donors to glycolipids and glycoproteins. The enzyme activity is associated with intact cells. Kinetic parameters and optimal ion concentrations have been determined for the glycosyltransferase activities detected when whole...
متن کاملFunction of mitochondrial complex-I and -IV in normal human and Parkinson's disease cybrids
Mitochondrial dysfunction has been implicated in the dopaminergic neurodegeneration, which characterizes Parkinson’s disease (PD). The activities of mitochondrial complexes I and IV were found to be reduced in the brains of PD patients (n = 4) as compared to age-matched controls (n = 4). This is tested in SH-SY5Y cell lines, transformed Rho0 cells, and in normal and PD cybrid cell lines. Cybrid...
متن کاملFunction of mitochondrial complex-I and -IV in normal human and Parkinson's disease cybrids
Mitochondrial dysfunction has been implicated in the dopaminergic neurodegeneration, which characterizes Parkinson’s disease (PD). The activities of mitochondrial complexes I and IV were found to be reduced in the brains of PD patients (n = 4) as compared to age-matched controls (n = 4). This is tested in SH-SY5Y cell lines, transformed Rho0 cells, and in normal and PD cybrid cell lines. Cybrid...
متن کامل