Characterisation of recombinant pyranose oxidase from the cultivated mycorrhizal basidiomycete Lyophyllum shimeji (hon-shimeji)

Table 3 Comparison of apparent kinetic constants of recombinant pyranose oxidase from Lyophyllum shimeji (Ls P2Ox), Trametes multicolor (Tm P2Ox) and Phanerochaete chrysosporium (Pc P2Ox) for various electron donor substrates.

Enzyme		K_m [mM]	k_cat [s^-1]	k_cat/K_m [mM^-1s^-1]	rel. k_cat/K_m^a [%]
Ls P2Ox	D-glucose	0.314	6.92	22.1	100
	D-galactose	3.84	1.02	0.265	100
	D-xylose	6.30	5.48	0.867	100
	L-sorbose	14.7	7.70	0.524	100
	melibiose	72.8	0.839	0.0115	100
Tm P2Ox	D-glucose	0.698	35.4	50.8	230
	D-galactose	8.09	2.73	0.337	127
	D-xylose	22.2	17.8	0.804	92.7
	L-sorbose	35.6	31.6	0.887	169
	melibiose	759	5.25	0.00691	60.1
Pc P2Ox	D-glucose^b	0.84	83.1	98.9	448
	D-galactose^b	2.94	4.87	1.66	626
	D-xylose^b	20.9	44.9	2.15	248
	L-sorbose^b	23.5	58.8	2.50	477
	melibiose	124.8	2.35	0.0189	164

^acatalytic efficiency k_cat/K_m relative to the value calculated for Ls P2Ox
^bdata taken from reference [9]
Kinetic data were determined at 30°C, pH 6.5 and using oxygen (air saturation) as electron acceptor.

ISSN: 1475-2859