To evaluate also long-term stability of our CLECs at the used reaction temperature (22 °C), half-life times (t1/2) of soluble enzyme and CLECs of HheG D114C were investigated. To facilitate the determination of t1/2 at 22°C, deactivation rate constants kd of soluble enzyme and CLECs at higher temperatures (>30°C) were determined. Using the Eyring equation , respective deactivation rate constants at 22°C could be extrapolated (Figure ), and deactivation energies as well as half-life times were determined (Table ). As a result, a half-life time of 64 days at 22°C was obtained for D114C CLECs, which is consistent with our reusability data (see below). In contrast, the respective t1/2 of soluble enzyme at 22°C is only 21 h. Hence, D114C CLECs exhibit a more than 60 times higher half life than soluble HheG D114C. Similar increases in half life upon CLEC formation have also been reported for other enzymes. Likewise, more energy is required for the deactivation of HheG D114C CLECs (46.8 kJ/mol) in comparison to soluble enzyme (36.3 kJ/mol), underlining once more the significant gain in stability upon cross-linking.