Temperature profile of trypsin from Z. ophiocephalus is depicted in Fig. 3c. The enzyme was active at temperatures from 30 to 80 ◦C with an optimum around 60 ◦C. The relative activity at 50 ◦C was about 85% of that at 60 ◦C. However, enzyme activity decreased rapidly at higher temperatures. The sharp decrease in hydrolysis of BAPNA might be attributed to irreversible protein denaturation due to the partial unfolding of the enzyme molecule. The optimal temperature for
Z. ophiocephalus protease was similar to trypsin from S. basilisca , higher than that of trypsin from B. capriscus
, which had an optimum temperature at 40 ◦C and lower than that of cuttlefish trypsin which had an optimum temperature at 70 ◦C .