ACTIVITY OF EUKARYOTIC INITIATION-FACTOR EIF-2 IN TERNARY COMPLEX-FORMATION WITH GTP AND MET-TRANSFER RNAF

  • 1 January 1979
    • journal article
    • research article
    • Vol. 254  (9) , 3201-3205
Abstract
Ternary complex formation between [rabbit liver] [3H]Met-tRNAf, [rabbit reticulocyte] [14C]H3-eIF-2 and GTP was measured on nitrocellulose filters. [3H]Met-tRNAf and [14C]H3-eIF-2 are present on the filter in equimolar amounts when ATP, creatine phosphate and creatine kinase (EC 2.7.3.2) are included in the reaction mixture. Under these conditions the factor is 100% active. With small amounts of factor significant losses occur due to adsorption to the wall of the reaction vessels, resulting in seemingly low activities of eIF-2. These losses can be prevented by the presence of stimulatory proteins which enhance the recovery of [3H]Met-tRNA and [14C] H3-eIF-2 on the filter but do not alter their ratio.