Isozyme patterns of branched chain amino acid trans aminase ec 220.127.116.11 in cultured morris hepatoma 7316 a
Tomita, Y.; Ichihara, A.; Masuji, H.; Sato, J.
Gann 67(3): 465-467
Cultured cells from rat Morris hepatoma 7316A contained isozymes I and II, but not isozyme III, of branched chain amino acid transaminase [EC 18.104.22.168]. They also contained tyrosine transaminase. Isozyme II and tyrosine transaminase [EC 22.214.171.124] were induced by addition of cortisol. These findings agree with in vivo findings. Prolonged culture of the cells for over 500 days caused deviation of the chromosome number and activity of both enzymes, and they were no longer affected by cortisol. A tumor formed by back transplantation of the cells showed the typical isozyme pattern of rapidly growing hepatomas, such as Yoshida ascites hepatomas, i.e., isozymes I and III. These results were discussed in relation to changes of gene expression during culture.