Various properties of immobilized terminal deoxynucleotidyl transferase from the cattle thymus

The effects of temperature, pH, and concentration of sodium cacodylate buffer on the activity of partially purified terminal deoxynucleotidyl transferase from cattle thymus immobilized on BrCN-Sepharose were studied. The enzyme retained at least 60% of the initial activity after 6 h of incubation at 30 degrees in 50 mM potassium phosphate buffer, pH 7.2 in the absence of substrate. Short-term activation of the enzyme during incubation was noticed. The maximum activity of the immobilized preparations was observed in 240-280 mM sodium cacodylate buffer in the reaction mixture, pH 7.5-7.9 at 37-40 degrees.