Characterization of trehalose synthase from Corynebacterium nitrilophilus NRC

Trehalose synthase (TSII) from Corynebacterium nitrilophilus NRC was successively purified by ammonium sulphate precipitation, ion exchange chromatography on DEAE-cellulose and gel filtration chromatography on Sephadex G-100 columns. The specific activity of the trehalose synthase was increased similar to 200-fold, from 0.14 U mg(-1) protein to 28.3 U mg(-1) protein. TSII was found to be a monomeric protein with a molecular weight of 67-69 kDa. Characterization of the enzyme exhibited optimum pH and temperature were 7.5 and 35A degrees C, respectively. The purified enzyme was stable from pH 6.6 to 7.8 and able to prolong its thermal stability up to 35A degrees C. The enzyme activity was inhibited strongly by Zn(2+), Hg(2+) and Cu(2+) and moderately by Ba(2+), Fe(2+), Pb(2+) and Ni(2+). Other metal ions Ca(2+), Mg(2+), Co(2+), Mn(2+) and EDTA had almost no effect.