Pullulanase mutant and preparation method thereof

A pullulanase and mutant technology, applied in the fields of botanical equipment and methods, biochemical equipment and methods, DNA preparation, etc., can solve the problems that thermal stability cannot fully meet the saccharification process, low catalytic efficiency, etc.
CN103484443AActive Publication Date: 2014-01-01JIANGNAN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
JIANGNAN UNIV
Publication Date
2014-01-01

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Abstract

The invention discloses a pullulanase mutant having a high specific activity and a high thermal stability, and a preparation method thereof. The mutant comprises one, two or three substituents relative to debranching Bacillus spp Pullulanase active amino acid residues and related with the thermal stability of pullulanase; and the active amino acid residues comprise 503th aspartic acid, and can be mutated to form arginine, phenylalanine and tryptophan or tyrosine, the above mutation improves the high specific activity and the high thermal stability of the pullulanase, and at least one of the cases comprising the rise of a best reaction temperature, the improvement of the thermal stability at a pH value of 4.0-5.0 and the improvement of the specific activity at a pH value of 4.0-5.0 is realized. The mutant is more suitable for the starch saccharification production process than wild pullulanase.
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Description

[0001] This application is a divisional application with the patent number: 201210256804.9, the application date: July 23, 2012, and the patent name: a pullulanase mutant and its preparation method. technical field

[0002] The invention relates to a mutant of pullulanase and a preparation method thereof, in particular to a technology for improving the specific activity and thermal stability of pullulanase by using a site-directed mutation method of protein engineering, and belongs to the fields of genetic engineering and enzyme engineering. Background technique

[0003] Pullulanase (Pullulanase, EC3.2.1.41) is a debranching enzyme that can specifically cut α-1,6- Glycosidic bonds, used in the starch processing industry, can greatly improve the utilization rate and production efficiency of starch. Pullulanase is mainly used to prepare glucose by compounding with glucoamylase. Since the cutting efficiency of glucoamylase on the α-1,6-glucosidic bond in branched dextrin is ve...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
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