Fig 5.

Dependence of HvHMGCS and E. faecalis MvaS reaction rates on [acetoacetyl-CoA]. The specific activities of both HvHMGCS and E. faecalis MvaS for acetoacetyl-CoA were determined by monitoring the production of free CoA in the presence of DTNB at 412 nm in 100 mM Tris-Cl, pH 8. (A) HvHMGCS (■) assay containing 4 M KCl and saturating acetyl-CoA (250 μM). (B) Double-reciprocal plot of HvHMGCS (■) [acetoacetyl-CoA] dependence. (C) E. faecalis MvaS (●) assay containing saturating acetyl-CoA (500 μM). (D) Double-reciprocal plot of E. faecalis MvaS (●) [acetoacetyl-CoA] dependence. Data points represent specific activities at the indicated concentrations of acetoacetyl-CoA and were analyzed with GraphPad 5.0 or SigmaPlot 10.