|
Figure 1.
Figure 1. pH-dependence of k[cat]/K[m] for N35D BCX (•)
at 25°C towards the synthetic substrate orthonitrophenyl
β-xylobioside (ONPX[2]). Substitution of an Asp residue at
position 35 shifts the pH optimum from 5.7 for the WT protein to
4.6 for the N35D mutant. The activity profile follows
ionizations with pK[a] values of 3.5 and 5.8 in the N35D enzyme
(—) and 4.6 and 6.7 in the WT enzyme (- - -) [McIntosh et al
1996]. The data points, shown only for N35D BCX, were fitted as
described in Materials and Methods.
|
