CLONING, PURIFICATION AND CHARACTERIZATION OF A NOVEL RECOMBINANT TREHALOSE SYNTHASE (TreS) FROM Acidiplasma sp. MBA-1

摘要

Trehalose, a nonreducing disaccharide, can be commercially produced using maltose from microorganisms. An intramolecular transglycosylase enzyme called trehalose synthase (TreS) can catalyze the conversion of maltose to trehalose in a single step reaction. Hence, in our study a novel gene TreS encoded with 562 amino acids was cloned from Acidiplasma sp. MBA-1 and expressed into E. coli BL21 (DE). HPLC results suggested that it could catalyze the conversion between maltose and trehalose in one step. The conversion of trehalose from maltose was about 43.62% in our study. At the same time, TreS produced about 23.85% glucose as a by-product after 10h of incubation. SDS page results showed that the purified recombinant enzyme has a molecular weight of 65.9kDa. The recombinant TreS showed its optimal activity at 40°C and its optimum pH was 6.5. Our study shows that the enzyme was not thermostable and its activity was increased by 1mM EDTA, Mn2+ and Li+ whereas Cu2+and Ni2+ strongly inhibited the enzyme activity.