Improvement of PersiXyn2 activity and stability in presence of Trehalose and proline as a natural osmolyte

Abstract

Compatible solutes or osmolytes stabilize proteins against different stress conditions. In this study, the effect of trehalose and proline against pH and thermal stress is examined on PersiXyn2. Trehalose and proline lowered the optimum pH of PersiXyn2 and increased the optimum temperature of its activity, which is more desirable for its industrial application. These osmolytes improved PersiXyn2 storage stability for a long 24-day period. Also, both osmolytes retained the catalytic activity of the enzyme in the presence of different concentrations of metal ions but trehalose had the most effect in the presence of Mg2+ and proline had most significant effect in the presence of Mn2+. In addition, the effect of detergents on the enzyme in the presence of proline and trehalose increased the activity of PersiXyn2. Chemical stability studies using urea as a denaturant indicated that both of the osmolytes improved the conformational stability of PersiXyn2. According to molecular dynamic studies, a definite change in conformation of PersiXyn2 was detected in the presence of proline and trehalose. Based on findings in the current study, given the importance of xylanases activity and stability in extreme conditions for industrial applications, two natural osmolytes were able to activate and stabilize PersiXyn2.