Table 1. Comparison of K_m and V_max values of HexM toward a neutral and a negatively charged artificial substrate with those of other Hex isozymes.

Hex	MUG Km (mmol/l)	MUG Vmaxa	MUGS Km (mmol/l)	MUGS Vmaxa	Reference
M (μμ)b	1.10 ± 0.06	4.7 ± 0.1	0.21 ± 0.01	3.13 ± 0.03	PRc
A (αβ)	0.67 ± 0.06	9.7 ± 0.3	0.26 ± 0.02	1.32 ± 0.03	PR
S (αα)	1.5 ± 0.2	2.0 ± 0.1d	0.3 ± 0.1	0.94 ± 0.04d	7
B (ββ)	0.71 ± 0.1	14.5 ± 0.5	NDe	NDe	7

^aMoles (MU) h⁻¹ g⁻¹ (Hex).

^bIndicates a homodimer of our α-based hybrid subunit.

^cPresent report.

^dThese values may be low due to the presents of significant amounts of inactive HexS (an unstable isozyme).

^eNot determined because of insufficient activity toward MUGS (MUG/MUGS ~1/300).