In vitro and in vivo characterization of three Cellvibrio japonicus glycoside hydrolase family 5 members reveals potent xyloglucan backbone-cleaving functions

Table 1 Activity of CjGH5_4 enzymes against different polysaccharide substrates

Enzyme catalytic domains	Substrate	K_m mg mL⁻¹	k_cat s⁻¹	Specific activity µmol (min mg)⁻¹
CjGH5D	XyG	< 0.025	30.3 ± 0.4	43.3 ± 1.9
CjGH5E	XyG	0.020 ± 0.002	10.3 ± 0.1	15.1 ± 0.1
	Hydroxyethylcellulose (HEC)	ND	ND	0.070 ± 0.004
	Carboxymethylcellulose (CMC)	ND	ND	0.010 ± 0.002
CjGH5F	XyG	0.040 ± 0.003	52.4 ± 0.8	74.8 ± 4.1
CjGH5F	Hydroxyethylcellulose (HEC)	ND	ND	0.090 ± 0.003

Assays conducted at pH 7.5 (CjGH5D and CjGH5E) or pH 7 (CjGH5F). Recombinant enzymes were incubated at 50 °C (CjGH5D and CjGH5F) or 55 °C (CjGH5E) with the different tested substrates
ND not determined due to poor specific activity