[Immunochemical characteristics of hydrocortisone induced and hydrocortisone non-induced rat liver tyrosine aminotransferase isoenzymes].

Two isoenzymes of tyrosine aminotransferase (induced and noninduced by hydrocortisone were isolated from rat liver tissue and subjected to chromatographic purification. Specific antibodies with high titer were obtained after immunization of rabbits by the inducible isoenzyme. The antigenic properties of the obtained tyrosine aminotransferase isoenzymes were compared after double immunodiffusion in agar and immunoelectrophoresis. The purified induced and non-induced isoenzymes were shown to possess both similar and different antigenic determinants. The data obtained suggest that differences in antigenic properties of the tyrosine aminotransferase isoenzymes reflect those variations in their structure, which are expressed as various thermostability, sensitivity to proteolytic enzymes and substrate specificity.