Effect of temperature on the purified TcAAD. The enzyme sample was heated at 58°C for various time intervals. Aliquots of the sample were taken at 0, 2, 4, 8 or 16 min analyzed by SDS-PAGE (A) and assayed for AAD activity. The thermal inactivation kinetics of AAD activity was plotted (B). E0 and Et are original activity and residual activity after being heated for different time intervals. Data are means of three experiments.