A kind of amylosucrase mutant and its preparation method and application

Abstract

The invention discloses an amylosucrase mutant as well as a preparation method and application thereof, and belongs to the field of gene engineering and enzyme engineering. According to the amylosucrase mutant as well as the preparation method and application thereof, glycine at the 399th site of amylosucrase derived from Deinococcus Geothermals is mutated into serine, and the obtained amylosucrase mutant is applied to the production of turanose; the yield of the turanose obtained through the amylosucrase mutant under the conditions that the temperature is 35 DEG C, and the initial pH value is7.0 reaches up to 32% and is 2 times of the conversion rate of the turanose produced through wild enzymes; and therefore, the amylosucrase mutant can be applied to preparation of the turanose, so that the conversion rate of the turanose is further increased.

Description

technical field

[0001] The invention relates to a starch sucrase mutant and its preparation method and application, belonging to the fields of genetic engineering and enzyme engineering. Background technique

[0002] Turanose is formed by linking a molecule of glucose and a molecule of fructose with α-1,3 glycosidic bonds. As an isomer of sucrose, its sweetness is only half of that of sucrose. It has the characteristics of easy crystallization, high solubility, slow hydrolysis rate, easy reconciliation with other substances, and no fermentation by cariogenic microorganisms. It is suitable for people suffering from obesity, hyperlipidemia, high blood pressure, and diabetes. Therefore, turanose has the potential to become a new generation of low-calorie functional sweetener in the food field. In addition, turanose is also widely used in the field of medicine, and can be used as an inhibitor of acid α-glucosidase for the medical diagnosis of Pompe disease; it also has anti-inf...

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