<span style="mso-bidi-language:HI">Purification and characterization of trehalose-6-phosphate synthase from <i><span style="mso-bidi-language:HI">Saccharomycopsis </span></i><i><span style="mso-bidi-font-family:Arial;mso-bidi-language:HI">fibuligera </span></i><span style="mso-bidi-language:HI">A<span style="mso-bidi-font-family:Arial; mso-bidi-language:HI">11 </span></span></span>

Abstract

289-294Mutant <span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">A11, a mutant of Saccharomycopsis fibuligera Sdu with low acid and neutral trehalase was found to <span style="mso-bidi-font-family:Arial; mso-bidi-language:HI">accumulate over 18% (w/w) trehalose <span style="mso-bidi-font-family:Arial;mso-bidi-language: HI">from starch in its cells. In this study, trehalose-6-phosphate synthase <span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">(Tps1) was purified to homogeneity from this mutant, with a 30-fold increase in the specific enzyme activity, as compared to the concentrated cell-free extract, from initial cells. The molecular mass of the purified enzyme as determined by SDS-PAGE was 66 <span style="mso-bidi-font-family:Arial;mso-bidi-language: HI">kDa. The optimum pH and temperature of the purified enzyme were 6.6 and 37°C, respectively. The enzyme was activated by Ca<span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">2<span style="mso-bidi-language: HI">+, K+ and Mg2+, with K+ showing the highest activation at 35 mM. On the other hand, Mn<span style="mso-bidi-font-family:Arial;mso-bidi-language: HI">2+, Cu<span style="mso-bidi-font-family: Arial;mso-bidi-language:HI">2<span style="mso-bidi-language: HI">+, Fe3+, Hg2+ and Co<span style="mso-bidi-font-family:Arial;mso-bidi-language: HI">2+ inhibited the enzyme. The enzyme was also strongly inhibited by protease inhibitors such as iodoacetic acid, EOTA and PMSF. </span