Table 1.

Kinetic parameters of H. volcanii, E. faecalis, and H. sapiens HMGCS enzymes

Enzyme	Km (μM)		Vmax (μmol/min/mg)	kcat (s−1)	kcat/Km (s−1 mM−1)	ki, hymeglusin (nM)	kinact (min−1)
	Acetyl-CoA	Acetoacetyl-CoA
HvHMGCS	50 ± 6a	1.4 ± 0.1	5.3 ± 0.2	4.6 ± 0.2	92 ± 11	570 ± 120	17 ± 3
E. faecalis MvaSb	400 ± 60	0.5 ± 0.1	1.6 ± 0.3	1.1 ± 0.2	2.8 ± 0.2	700 ± 18	3.5 ± 0.6
H. sapiens HMGCSc	29 ± 7	NDd	0.7 ± 0.1	0.7	23	53.7	1.06

^aValues are means and standard error of the means.

^bData for E. faecalis HMGCS were previously reported by Skaff et al. (11).

^cData for H. sapiens HMGCS were previously reported by Rokosz et al. (23). The k_cat and k_cat/K_m values were not explicitly reported but were calculated by using the V_max and molecular weight.

^dND, not determined.