[Isolation of matrix RNA coding a tyrosine aminotransferase isoenzyme induced by hydrocortisone from rat liver polyribosomes].

Messenger RNA (mRNA) capable of coding hydrocortisone induced isoenzyme of tyrosineaminotransferase (TAT) was isolated and purified approximately 5000 times. Highly specific rabbit antibodies to the isoenzyme were obtained. Using these antibodies a specific antibody immunoadsorbent with a high capacity for specific binding to TAT was prepared. From total rat liver polyribosomes induced by hydrocortisone a specific fraction synthesising TAT was isolated by fractionation on the antibody immunoadsorbent. Affinity chromatography using poly(U)--Sephadex 4B allowed to isolate a poly(A)-containing RNA from this polyribosome fraction. The mRNA (15-16S) acts as a matrix in a cell-free protein synthesising system. The extent of purification of the mRNA was estimated by the synthesis of specific protein TAT in the cell-free system.