Table 4.

Kinetic parameters for the racemization of L- to D- and D- to L-alanine by alanine racemases from Gram-positive bacteria

	D to L direction			L to D direction
Enzyme [ref]	Km(mM)	Vmax(U/mg)a	kcat(min-1)	Km(mM)	Vmax(U/mg)a	kcat(min-1)
AlrSP [21]	2.1b	87.0b	NR	1.9b	84.8b	NR
AlrGS [76]	2.7c	1400c	NR	4.3c	2550c	NR
AlrSL [77]	0.4c	NR	3800c	0.4c	NR	3300c
AlrBA [36]	2.8b	101b	NR	NR	NR	NR
AlrEF [78]	2.2c	1210c	~2340c	7.8c	3570c	~2340c

^aOne unit is defined as the amount of enzyme that catalyzes racemization of 1 μmol of substrate per minute.

^bAt 23°C. ^cAt 37°C. NR: not reported.