NONIDEAL SIZE-EXCLUSION CHROMATOGRAPHY OF EUKARYOTIC PROTEIN-SYNTHESIS INITIATION-FACTOR-2

Eukaryotic protein synthesis initiation factor 2 (eIF-2), a heterotrim er, was chromatographed on high performance (Superose 6) and standard (Ultrogel AcA 34 and Sephacryl S-300) size exclusion chromatography (S EC) media. The retention volume of eIF-2 on the Superose 6 column was higher than expected from its M(r) and elution of a beta gamma eIF-2 d imer was seen. Conversely, on AcA 34 and Sephacryl S-300 most of the e IF-2 was eluted at its expected position, considering its ellipsoidal structure, as the heterotrimer. Elution of the beta gamma heterodimeri c eIF-2 may therefore be promoted by Superose 6 high performance SEC w hich therefore provides a means for its rapid preparation for studies in protein synthesis initiation.