[Aspartate kinase from the cyanobacteriium Plectonema boryanum infected with the cyanophage LPP-3].

The effect of development of cyanophage infection on the activity of aspartate kinase of Plectonema boryanum has been studied. It has been determined that activity of aspartate kinase increased during early period of reproduction of cyanophage. It coincided in time with the increase of the level of amino acids of aspartate family. Isoenzymes of aspartate kinase were isolated from the infected cells purified and studied. Expression of viral genome is accompanied with the appearance of four new isoenzymes determined by virus. The revealed aspartate kinases are not subject of regulation by amino acids (the end-products of biosynthesis) according to the principle of feed-back inhibition.