Cloning And Expression Of α-Glucosidase From Thermo Thermophilus HB27 In Escherichia Coli And Analysis Of α-Glucosidase Properties

Alpha-glucosidase(EC3.2.1.20) is usually named maltase and a-transglucosidase which can hydrolyse a-glucosidic linkages in poly-, oligo- and disaccharides. It is the key enzyme for yielding iso-maltooligosaccharide. Iso-maltooligosaccharide, one of the oligosaccharide, has special physiological function and benefits to human body. At present, most of a-glucosidase used in industry come from Aspergillus niger and Aspergillus oryzae.The gene which encoding a-glucosidase was researched in the thesis. The cloned gene was expressed in E.coli and the properties of a-glucosidase was determinated. About 1.6kb DNA fragment was obtained by PCR from total DNA of Thermus thermophilus HB27 using a specific 5'-end and 3'-end primer. PCR product was cleaved with restriction enzyme Nhe I and Hind III and ligated into the Nhe I /Hind III-digested restriction site of vector pET28a(+). After transformation of the competent E.coli, transformants were obtained. When the...