Xylo- and cello-oligosaccharide oxidation by gluco-oligosaccharide oxidase from Sarocladium strictumand variants with reduced substrate inhibition

Table 4 Substrate inhibition of GOOX and mutant variants

Substrate	GOOX			GOOX-VN			GOOX-V			Y300A	W351A
Substrate	V_i/V_max(%)	K_i(mM)^*	n ^H**	V_i/V_max(%)	K_i(mM)	n ^H	V_i/V_max(%)	K_i(mM)	n ^H	Y300A	W351A
Glucose	NI			NI			NI			NI	NI
Cellobiose	32	2.51 ± 0.18	2.2	38	3.2 ± 0.2	1.8	35	2.7 ± 0.2	1.3	NI	NI
Cellotriose	34	1.33 ± 0.13	1.4	42	1.9 ± 0.2	1.3	37	1.56 ± 0.13	1.9	NI	NI
Cellotetraose	34	1.49 ± 0.10	1.8	42	2.20 ± 0.16	1.5	36	1.61 ± 0.12	1.6	NI	NI
Cellopentaose	35	1.53 ± 0.13	1.4	53	1.66 ± 0.18	1.3	43	1.36 ± 0.11	1.4	NI	NI
Cellohexaose	44	0.62 ± 0.09	1.3	54	0.81 ± 0.10	1.1	44	0.83 ± 0.07	1.2	NI	NI
Xylose	ID			ID			ID			NI	NI
Xylobiose	51	3.1 ± 0.2	1.2	70	5.0 ± 0.6	1.1	57	3.0 ± 0.2	1.5	NI	NI
Xylotriose	45	2.99 ± 0.19	1.3	75	3.6 ± 0.4	1.2	49	3.0 ± 0.3	1.5	NI	NI
Xylotetraose	57	1.94 ± 0.16	1.3	NI			62	1.82 ± 0.15	1.3	NI	NI
Xylopentaose	53	2.0 ± 0.3	1.4	NI			56	2.0 ± 0.4	1.4	ND	NI
Xylohexaose	61	1.6 ± 0.2	1.5	NI			54	2.2 ± 0.3	1.3	NI	NI

^*Substrate inhibition kinetics derived from eq. 2. ^**Hill coefficient.
^-Values could not be calculated due to no detectable activity.
^NINo inhibition detected at tested substrate concentrations; ^IDInsufficient data to calculate inhibition kinetics; however inhibition was observed at xylose concentrations greater than 800 mM; ^NDNot determined.

ISSN: 2731-3654