Effect of elastase on elongation factor 1 from wheat germ

Elongation factor 1, species A, B and C, were isolated from wheat germ and purified to homogeneity by the following steps: supernatant 100 000 xg, precipitation with ammonium sulphate and column chromatography: Sephadex G-150, DEAE-Sephadex A-50 and hydroxylapatite. On the second column the activity was divided into three peaks: EF1 A, B and C. The pure proteins EF1A, B and C (molecular weight 61 000, 48 000 and 12 500 D, respectively) were treated with elastase. Two products of EF1A digestion, polypeptides b and c, were isolated. The molecular weights of polypeptides b and c were similar to molecular weight of species B and C of EF1. Both digestion products were active in binary complex formation with GDP and in binding of Phe-tRNA to ribosomes. EF1B was converted to polypeptide c or similar and EF1C was rather resistant to elastase treatment.