| Abstract: | Distribution of the aminoacyl-tRNA synthetase activity has been studied in the normal rabbit liver cells and in the model of protein synthesis damage, i.e. under experimental myocardial infarction (EMI). The activity of a number of aminoacyl-tRNA synthetases in postmitochondrial and postribosomal extracts from rabbit liver homogenate has been determined to increase 12 h after EMI. Gel filtration of the postribosomal extract on Sepharose 6B shows that the activity of aminoacyl-tRNA synthetases is distributed among the fractions with Mr 1.82 x 10(6), 0.84 x 10(6) and 0.12 = 0.35 x 10(6). The first two fractions (high-molecular-weight aminoacyl-tRNA synthetase complexes) contain arginyl-, glutamyl-, isoleucyl-, leucyl-, lysyl- and valyl-tRNA synthetases, whereas the low-molecular-weight fraction contains alanyl-, arginyl-, glycyl-, phenylalanyl-, seryl-, threonyl-, tryptophanyl- and tyrosyl-tRNA synthetases. In a case of EMI all the aminoacyl-tRNA synthetases translocate from the complexes with Mr 1.82 x 10(6) into the complexes with Mr 0.84 x 10(6), what provided evidence for the possibility to regulate protein synthesis by changes in compartmentalization of aminoacyl-tRNA synthetases. |
