kd: Inactivation rate constant
Inactivation Rate Constant (kd)
Chromatography (HPLC, TLC)
50 mM Tris-HCl
The half-life of protein activity was measured by placing 100 µL of proteins at 60 °C. Samples were removed at different times and then cooled to 22 °C. Second-order thermal deactivation was fitted to:
1/A(t) = 1/A0 + kt
where A(t) is the activity at time t of the heat treatment, A0 is the initial activity before heat treatment, and k is the inactivation rate constant. Half-life (t1/2) at 60 °C was calculated as t1/2 = 1/(100*kd). Retained activity (RA) after time t of heating was calculated as A(t)/A0.