FIGURE 4.

Effect of TbTim17 antibody on in vitro import of COIV into mitoplast. A, in vitro import of COIV into isolated T. brucei mitoplasts was performed in the presence of various concentrations of anti-TbTim17 IgG and IgG purified from preimmune serum. The radiolabeled substrate, T. brucei COIV, an N-terminal signal-containing protein, was synthesized using a coupled transcription/translation system as described under “Experimental Procedures.” The precursor (p) and mature (m) products are indicated. B, the intensity of the imported protein bands was quantified, and the percent reductions relative to no-antibody controls were calculated from three independent experiments and plotted against IgG concentrations.