Immunological specificity of the chloroplast elongation factors G and T u of spinach leaves

Abstract

Antisera prepared against the chloroplast elongation factors G (EF-G chl) and T u (EF-T u chl) from spinach leaves were found to immunoprecipitate specifically only spinach EF-G chl and EF-T u chl, respectively. Anti-EF-G chl antiserum inhibited polyphenylalanine synthesis in a E. coli system dependent upon added EF-G chl. However, at higher concentrations the antiserum also inhibited the activity of systems containing EF-Gs from chloroplasts of tobacco, from Chlorella vulgaris mitochondria and from two bacteria. In addition, in vitro protein synthesising systems prepared from the cytoplasm of spinach or yeast were inhibited at higher concentrations of antiserum. The results are compared with those obtained previously with an antiserum prepared against mitochondrial EF-G from the alga C. vulgaris.