The extent of thermal enzyme denaturation also depends on the activation entropy (S*d) of this event, which expresses the amount of energy per degree involved in the transition from a native to a denatured state [8]. As shown in Table 1,consistently with the increase in the disorder or randomness degree consequent to such a transition, the S*d values were positive (599.59–610.49 J/mol K) at all temperatures at which
A. foetidus protease was tested. In addition, they were higher than those reported for the above proteases from A. awamori (−93.5 ≤ S*d ≤ 126.5 J/mol K) [15], N. alba (S*
d = −69.99 J/mol K)[11] and A. fumigatus (−69.5 ≤ S*d ≤ −68.2 J/mol K) [7].