Purification of free eukaryotic initiation factors eIF-4A and eIF-4D on cibacron blue F3G-A

Abstract

The eukaryotic initiation factors eIF-4A and eIF-4D are almost exclusively found in the supernatant of a reticulocyte lysate. The basic steps of general purification schemes failed because these factors do not bind to Sepharoseheparin or, in the case of eIF-4A, to phosphocellulose and a new procedure had to be devised. Cibacron Blue F3G-A proved to be a successful alternative in the purification of these factors from the excessive load of proteins found in the supernatant.