Table 1. Kinetic parameters of CbCel9A/Cel48A wild-type and its truncational mutants on cellulosic substrates a .
Enzyme | PASC
b
|
Avicel (µM glucose equivalents/min/µM enzyme) | Filter paper (µM glucose equivalents/min/µM enzyme) | ||
---|---|---|---|---|---|
k cat (s-1) | K m (mg ml-1) | k cat/K m (s-1 ml mg-1) | |||
WT | 2.0±0.3 | 2.6±1.0 | 0.8±0.3 | 22.8±1.3 | 13.1±0.3 |
TM1 | 1.6±0.2 | 1.8±0.6 | 0.9±0.3 | 10.2±1.0 | 7.0±1.8 |
TM2 | 0.2±0.0 | 1.5±0.6 | 0.1±0.0 | 2.2±0.1 | 1.3±0.2 |
TM3 | 5.1±0.3 | 2.3±0.3 | 2.2±0.3 | 3.5±0.7 | 4.5±0.6 |
a The reactions were performed in a 50 mM sodium-citrate buffer with 150 mM NaCl (pH6.0) at 75°C.
b PASC: phosphoric acid swollen cellulose.