[Methylation of rat liver tRNA under different experimental conditions].

The primary biochemical and conformational changes in tRNA of the albino rat liver were studied under conditions of X-ray irradiation and under the effect of prozerine and nicotinic acid. Under the effect of these factors the rate of the liver tRNA methylation increases by 45, 103 and 112%, respectively. The melting point of the tRNA control preparations is 61 degrees C, under the the effect of irradiation--57 degrees C, under the prozerine and nicotinic acid effect--52 degrees C. Hyperchromia of the tRNA control and experimental preparations is equal to 28, 30 and 34%, respectively. No changes were found in sedimentation coefficient of the tRNA control and experimental preparations.