Figure 4.

Rate of inactivation at 42.5°C of the wild-type and altered enzymes. In (A), the experiment was conducted in 20 mM KPO₄, 20 mM NaCl, pH 7.0 buffer, whereas in (B) 10% glycerol was also present. Wild type (filled circles), M10L (open squares), I123R (filled triangles), I123W (open triangles), T367R (open diamonds), and T367S (open circles). (Identical symbols are used in [A] and [B] for the enzymes). All enzymes are at a concentration of 1 mg/mL. The enzyme activities are expressed as E/E₀ (observed activity/initial activity).