[Study of the properties of leucyl-tRNA synthetase from porcine myocardium in a normal state and in experimental ischemia]. / Izuchenie svoistv leitsil-tRNK-sintetazy iz miokarda svin'i v norme i pri éksperimentalnoi ishemii.

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. Reverse redistribution of the leucyl-tRNA-synthetase activity was found in the fractions of free enzyme and high molecular complex depending on duration of ischemia.