Figure 4.

Biochemical characterization of mevalonate-3-kinase (A–C) and mevalonate-3-phosphate-5-kinase (D–F). (A) Activity at pH 8.5 over a temperature range of 25–60 °C in 5 °C increments. (B) Residual activity after the sample had been incubated at the indicated temperature for 1 h and then assayed at 55 °C and pH 8.5. (C) Activity at 25 °C over a pH range of 6.5–9.5 in pH increments of 0.5. (D) Activity at pH 8.0 over a temperature range of 25–60 °C in 5 °C increments. (E) Residual activity after the sample had been incubated at the indicated temperature for 1 h and then assayed at 60 °C and pH 8.0. (F) Activity at 60 °C over a pH range of 6.5–9.5 in pH increments of 0.5. Curve fits in panels A–F were generated by a Stineman function³⁴ and included simply to highlight data trends.