| Abstrakt: |
Dexamethasone, insulin, and serum induce an additive increase in the activity of tyrosine aminotransferase (l-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) in hepatoma cells in tissue culture. By the criteria of immunotitration, heat stability, and electrophoresis on polyacrylamide gels, we have shown previously that all three effectors increase the cellular concentration of the same protein (Gelehrter, T. D., Emanuel, J. R., Spencer, C. J. (1972) J. Biol. Chem.247, 6197–6203). During the course of these studies however, we observed an apparent isozyme of tyrosine aminotransferase whose activity is not enhanced by these three inducers. |
