Liang Likun, Chi Zhenming, Gao Lingmei, Ma Liyan
UNESCO Chinese Center of Marine Biotechnology, Ocean University of China, Yushan Road, No.5, Qingdao, China.
Indian J Biochem Biophys. 2006 Oct;43(5):289-94.
Mutant A11, a mutant of Saccharomycopsis fibuligera Sdu with low acid and neutral trehalase was found to accumulate over 18% (w/w) trehalose from starch in its cells. In this study, trehalose-6-phosphate synthase (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 kDa. The optimum pH and temperature of the purified enzyme were 6.6 and 37 degrees C, respectively. The enzyme was activated by Ca2+, K+ and Mg2+, with K+ showing the highest activation at 35 mM. On the other hand, Mn2+, Cu2+, Fe3+, Hg2+ and Co2+ inhibited the enzyme. The enzyme was also strongly inhibited by protease inhibitors such as iodoacetic acid, EDTA and PMSF.
突变体A11是扣囊复膜孢酵母Sdu的一个突变体，其酸性和中性海藻糖酶含量较低，发现该突变体能够在细胞内从淀粉中积累超过18%（w/w）的海藻糖。在本研究中，从该突变体中纯化得到了均一的海藻糖-6-磷酸合酶（Tps1），与初始细胞的浓缩无细胞提取物相比，其比酶活性提高了30倍。通过SDS-PAGE测定，纯化酶的分子量为66 kDa。纯化酶的最适pH和温度分别为6.6和37℃。该酶被Ca2+、K+和Mg2+激活，其中K+在35 mM时表现出最高的激活作用。另一方面，Mn2+、Cu2+、Fe3+、Hg2+和Co2+抑制该酶。该酶也受到碘乙酸、EDTA和PMSF等蛋白酶抑制剂的强烈抑制。
Zotero 插件