... enzyme’s inactivation kinetics, the inactivation course of TNXI in the presence of various metal concentrations and metal combinations was determined Figure shows the inactivation courses of apo-TNXI ... courses of apo-TNXI and of TNXI in the presence of mm concentrations of each of the three divalent cations (Mg2+, Mn2+, or Co2+) With the exception of apo-TNXI, whose inactivation was first-order, ... (kcal/mole·K) Thermostability of class II xylose isomerases TTXI ECXI TNXI TNXI* Fig Effect of metals on the Tm values of class II XIs DT is the difference between Tm (enzyme in the presence of lM single...