Characterization of Purified Est_p6 Enzyme

The optimal pH of purified Est_p6 was determined under standard conditions. The buffers used were 50 mM sodium citrate (pH 2.55-6.16), MOPS (pH 5.69-8.10), Tris–HCl (pH 7.12-9.10), CHES (pH 9.11-10.09), and CAPS (pH 9.78-11.06). pH stability was determined by incubating the assays at pH values ranging from 4.63 to 10.72 for ~3 days and measuring the residual activity. The optimal temperature was determined under standard conditions in the range 0-60°C. Temperature stability was determined by incubating the assays at temperatures ranging from 30 to 50°C for 30 min to 100 hr and measuring the residual activity.