Table 2.

Kinetic parameters of Xyl2

Activity	Endo-β-(1,4)-xylanase						β-d-xylosidase
Substrate	RBB-xylan						pNP-β-Xyl
	SA (µmol min−1 mg−1)a	Opt. pH	K M (mM)	Vmax (µM min−1)	k cat (min−1)	k cat/K M (mM−1 min−1)	SA (µmol min−1 mg−1)b	Opt. pH	k cat/K M (mM−1 min−1)c
Xyl2	27.2	7.0 − 8.0	40 ± 13	2.9 ± 0.6	16.0 ± 1.6	(400 ± 2) × 10−3	0.19	6.0	(61 ± 3) × 10−3

^aSA, specific xylanase activity, calculated as μmol Remazol Brilliant Blue R liberated per mg of enzyme per minute at pH 8.0 and 40 °C

^b SA specific β-d-xylosidase activity, calculated as μmol pNP liberated per mg of enzyme per minute at pH 6.0 and 40 °C

^cThe k _cat/K _M ratio for the β-d-xylosidase activity was calculated directly from a progress curve