Studies on glycosidases : Recognition of substrate and alteration of function

我克隆了葡聚糖酶基因，发现它与一些糖淀粉酶基因有相似性，可以确定与α-1，4或α-1，6糖苷键结合的区域。此外，还分离了异麦芽三糖葡聚糖酶基因，并在E.coll中进行了表达。淀粉分支酶(BE)与淀粉的生物合成有关，它催化α-1，4-葡萄糖苷键的水解，并将其转移到α-1，6点。我克隆了两种类型的这种酶，并成功地在E，coll中表达了它们。对这些同工酶的嵌合酶进行了分析。N-末端是决定与直链淀粉或支链淀粉亲和力的重要因素。并对不同性质的嵌合酶进行了制备和分析。

I cloned the glucodextranase gene, and found that showed the similarity to some of glucoamylase, it is possible to determine the region for bind to α-1,4 orα-1,6 glucosidic linkages. Also the isomaltotrio-dextranase gene was isolated and expressed in E. coll. The expressed enzyme was analyzed.Starch branching enzyme (BE) is concern to biosynthesis of starch, which catalyze the hydrolysis ofα-1,4-glucosidic linkage and transferring it to make α-1,6 point. I cloned two types of this enzyme, and succcessed to express them in E, coll. Chimeric enzymes from these isozymes were analyzed. N-terminal was important to determine the affinity to amylose or amylopectin. And some chimeric enzymes which have different properties were made and analyzed.