[Interaction of eukaryotic aminoacyl-tRNA-synthases with polyribosomes].

Properties of rabbit liver tissue aminoacyl-tRNA synthetases, associated with polyribosomes, were studied under conditions of normal state and within 12 hrs after simulation of myocardium infarction. Under conditions of myocardium infarction the activity of some forms of aminoacyl-tRNA synthetase was decreased in polyribosomes and protein fractions, liberated from polyribosomes by means of washing with buffer containing 0.5 M KCl.

[The role of long-chain acyl-CoA in the disturbances of oxidative phosphorylation in the myocardium].

The effect of intramitochondrial acyl-CoA on the respiration of rabbit heart mitochondria in different metabolic states was studied. Acyl-CoA inhibited O2 consumption by 11% in State 4 and by 6% in State 3. However, the effect of acyl-CoA was more pronounced (20%) in the intermediate state of respiration between State 4 and State 3.

[Study of the properties of leucyl-tRNA synthetase from porcine myocardium in a normal state and in experimental ischemia].

Catalytic properties and thermostability of leucyl-tRNA-synthetase were studied both in free form and in the form of high molecular complexes, isolated from pig myocardium under normal state and after 15 min and 30 min ischemia. Km values of free and associated forms of leucyl-tRNA-synthetase were similar either in normal state or after 15-30 min ischemia. Complex-formation protected the enzyme from thermic inactivation under normal and ischemic conditions.

[Distribution of aminoacyl-t-RNA-synthetase activity in rabbit liver cells during disruption of protein biosynthesis in experimental myocardia infarct].

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).

[Comparative characteristics of tRNA-methyltransferases from rabbit liver and myocardium under normal conditions and in experimental ischemia].

Comparative studies of the state of aggregation and activity of tRNA-methyltransferases in cytosol (105,000 X g supernatant) from normal and ischemic rabbit liver and myocardium were carried out. The optimal conditions (pH, protein concentration, ionic composition of incubation mixture) for the determination of activity of tRNA-methyltransferases were elaborated. The protein fraction precipitated at 55% saturation of ammonium sulfate was shown to inherit the highest activity of tRNA-methyltransferases.