Figure 5.

Experiment-1 of the time courses (y, mean $\pm \mathrm{SE},$ umol/mg protein) of crude GH5-p4818Cel5_2A enzyme preparation incubated with the carboxymethyl cellulose (CMC) and Avicel substrate buffers in the presence or absence of N₂ gas purging for up to 90 and 180 min, respectively, in examining the effects of auto-oxidation on GH5-p4818Cel5_2A activity. (A) Responses (y, mean $\pm \mathrm{SE}$, n = 4 at each time point) of the p4818Cel5_2A enzyme preparation incubated with the CMC substrate buffer without N₂ gas purging and DTT (5 mM) for up to 90 min established according to a quadratic model (model parameter estimates $\pm \mathrm{SE})$: $Y=-0.041\left(\pm ,0.011\right)x+6.7e^{-4}{(\pm 1.1e^{-4})\mathrm{x}}^2$, P = 0.342 for the intercept; P = 0.001 for the linear parameter estimate; and P < 0.0001 for the quadratic parameter estimate; ${\mathrm{R}}^2=0.777,\mathrm{n}=28$ (B) Responses (y, mean $\pm \mathrm{SE}$, n = 4 at each time point) of the GH5-p4818Cel5_2A enzyme preparation incubated with the Avicel substrate buffer without N₂ gas purging and DTT (5 mM) for up to 180 min established according to a cubic model (model parameter estimates $\pm \mathrm{SE})$ as: $Y=0.253{\left(\pm ,0.059\right)\mathrm{x}}^{}-0.193{\left(\pm ,0.048\right)\mathrm{x}}^2+0.039{(\pm 0.010)\mathrm{x}}^3$, P = 0.064 for the intercept; P = 0.001 for the linear parameter estimate; P = 0.002 for the quadratic parameter estimate; and P = 0.003 for the cubic parameter estimate; ${\mathrm{R}}^2=0.662,\mathrm{n}=20$; (C) Responses (y, mean $\pm \mathrm{SE}$, n = 4 at each time point) of the GH5-p4818Cel5_2A enzyme preparation incubated with the CMC substrate buffer with N₂ gas purging and DTT (5 mM) for up to 90 min established according to a linear model (model parameter estimates $\pm \mathrm{SE})$: $y=0.856\left(\pm ,0.189\right)+0.042\left(\pm ,0.003\right)x,$ P = 0.0001 for the intercept; and P < 0.0001 for the slope; ${\mathrm{r}}^2=0.874$, n = 28; (D) Responses (y, mean $\pm \mathrm{SE}$, n = 12 at each time point) of the GH5-p4818Cel5_2A enzyme preparation incubated with Avicel substrate buffer with N₂ gas purging and DTT (5 mM) for up to 180 min established according to a linear model (model parameter estimates $\pm \mathrm{SE})$: $Y=0.242\left(\pm ,0.91\right)+0.003\left(\pm ,0.001\right)x$, P = 0.009 for the intercept and P = 0.001 for the linear parameter estimate; ${\mathrm{r}}^2$ = 0.145, n = 72; (E) Linear part (y, mean $\pm \mathrm{SE}$, n = 4 at each time point) of the (0, 7.5 and 15 min) the above-(C) the time course experiment with the p4818Cel5_2A enzyme preparation incubated with the CMC substrate buffer at 37 °C and pH 7.4 with N₂ gas purging and DTT (5 mM) established as (model parameter estimates $\pm \mathrm{SE})$: $y=0.148\left(\pm ,0.010\right)x$, P = 0.714 for the intercept; and P < 0.0001 for the slope $;{\mathrm{r}}^2=0.965,\mathrm{n}=12$; and (F) Linear part (y, mean $\pm \mathrm{SE}$, n = 12 at each time point) of the (0, 15 and 30 min) the above-(D) the time course experiment with the GH5-p4818Cel5_2A enzyme preparation incubated with the Avicel buffer at 37 °C and pH 7.4 with N₂ gas purging and DTT (5 mM) established as (model parameter estimates $\pm \mathrm{SE})$: $y=0.009\left(\pm ,0.002\right)x$, P = 0.631 for the intercept; and P = 0.0002 for the slope; ${\mathrm{r}}^2=0.315,\mathrm{n}=36$.