Expression of hormonally induced tyrosine aminotransferase in host liver and Morris hepatoma No. 7777 during cofactor depletion.

Cytoplasmic tyrosine aminotransferase (L-tyrosine: 2-oxoglutarate aminotransferase, EC2.6.1.5) was partially purified from host liver and Morris hepatoma No. 7777 grown in pyridoxine depleted rats. The animals were sacrificed six hours following the intraperitoneal administration of hydrocortisone hemisuccinate. Enzyme preparations were subsequently resolved by electrophoresis on polyacrylamide gels. Enzyme activity was detected histochemically in situ on the gels. Six and at least three enzymatically active protein peaks were detected in host liver and the hepatoma, respectively, by this method.