FIG. 5.

Enzymatic activity of the immunoprecipitated GGPP synthase. (A) Western blot analysis of GGPP synthase immunoprecipitated from 1 to 5 mg of proteins prepared from brain tissue. Arrows and numbers on the left indicate molecular size marker positions. (B) Time-dependent accumulation of radioactive compounds synthesized by GGPP synthase immunoprecipitated from 1 mg of brain proteins for up to 20 min. (C) GGPP synthase activity is dependent on the amount of immunoprecipitated protein in the assay. (D) GGPP synthase activity dependence on substrate (FPP) concentration. For this experiment, 0.5-mg aliquots of brain proteins were used.