Molecular and biochemical characterization of recombinant cel12B, cel8C, and peh28 overexpressed in Escherichia coli and their potential in biofuel production

Table 4 Enzyme kinetic parameters for cel12B, cel8C, and peh28^a

Enzyme	Substrate	V ^b_max (µmol/ml/min)	K ^c_m (mg/ml)	k ^d_cat (s⁻¹)	k _cat/K ^e_m (ml/mg/s)
cel12B	CMC	2.4 ± 0.2	19 ± 3	2.7 ± 0.2	0.14 ± 0.03
cel8C	CMC	39 ± 4	35 ± 6	85 ± 9	2.5 ± 0.7
peh28	Polygalacturonic acid	2.0 ± 0.5	0.87 ± 0.29	4.2 ± 1.0	4.9 ± 2.8

^aThe parameters were determined at 40 °C and pH 5.0 for peh28 using 0.05–0.55 mg/ml polygalacturonic acid and at 45 °C and pH 5.0 for cel12B and cel8C using 1–40 mg/ml CMC. Parameters are given as a mean of triplicates ± SE
^bMaximum velocity (at substrate saturation)
^cMichaelis–Menten constant (half-saturation constant)
^dTurnover number (enzyme concentration-independent specific rate at saturation)
^eCatalytic efficiency (specificity constant)

ISSN: 2731-3654